<PAGE>   1
 
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MARCH 18, 1996
 
                                                     REGISTRATION NO. 333-
================================================================================
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                            ------------------------
 
                                    FORM S-3
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933

                            ------------------------
 
                            ADVANCED MAGNETICS, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
 

<TABLE>
           <S>                                                       <C>
                       DELAWARE                                             4-2742593
           (STATE OR OTHER JURISDICTION OF                                (IRS EMPLOYER
            INCORPORATION OR ORGANIZATION)                            IDENTIFICATION NUMBER)
</TABLE>

 
                               725 CONCORD AVENUE
                         CAMBRIDGE, MASSACHUSETTS 02138
                                 (617) 354-3929
  (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF
                   REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)

                            ------------------------
 
                                JEROME GOLDSTEIN
                 CHAIRMAN OF THE BOARD, PRESIDENT AND TREASURER
                            ADVANCED MAGNETICS, INC.
                               725 CONCORD AVENUE
                         CAMBRIDGE, MASSACHUSETTS 02138
                                 (617) 354-3929
 (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                             OF AGENT FOR SERVICE)

                            ------------------------
 
                                   COPIES TO:
 

<TABLE>
             <S>                                                    <C>
                LESLIE E. DAVIS, ESQ.                                DAVID J. BEVERIDGE, ESQ.
              TESTA, HURWITZ & THIBEAULT                               SHEARMAN & STERLING
                  HIGH STREET TOWER                                    599 LEXINGTON AVENUE
                   125 HIGH STREET                                   NEW YORK, NEW YORK 10022
             BOSTON, MASSACHUSETTS 02110                                  (212) 848-4000
                    (617) 248-7000
</TABLE>

 
                            ------------------------
 
        APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:
  As soon as practicable after this Registration Statement becomes effective.

                            ------------------------
 
     If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box: / /
     If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, check the following box: / /
     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, check the following box and
list the Securities Act registration statement number of the earlier effective
registration statement for the same offering: / / 33-
     If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering: / / 33-
     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box: / /
 

<TABLE>
                        CALCULATION OF REGISTRATION FEE
=======================================================================================================================
                                                            PROPOSED MAXIMUM     PROPOSED MAXIMUM
TITLE TO EACH CLASS                         AMOUNT TO BE   OFFERING PRICE PER   AGGREGATE OFFERING       AMOUNT OF
OF SECURITIES TO BE REGISTERED             REGISTERED(1)        SHARE(2)             PRICE(2)        REGISTRATION FEE
- -----------------------------------------------------------------------------------------------------------------------
<S>                                        <C>                   <C>               <C>                  <C>
Common Stock, $0.01 par value per 
  share..................................  1,552,500 shares      $23.75            $36,871,875          $12,714.50
=======================================================================================================================
<FN>
 
(1) Includes 202,500 shares subject to an overallotment option granted by the
    Company to the Underwriters.
(2) Estimated solely for purposes of calculating the registration fee pursuant
    to Rule 457(c) under the Securities Act of 1933, as amended, based upon the
    average of the high and low sales prices of such Common Stock as reported by
    the American Stock Exchange on March 13, 1996.
</TABLE>


                            ------------------------
 
     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THIS REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE SECURITIES AND EXCHANGE COMMISSION, ACTING
PURSUANT TO SAID SECTION 8(A), MAY DETERMINE.

================================================================================

<PAGE>   2
 
     INFORMATION CONTAINED HEREIN IS SUBJECT TO COMPLETION OR AMENDMENT. A
     REGISTRATION STATEMENT RELATING TO THESE SECURITIES HAS BEEN FILED WITH THE
     SECURITIES AND EXCHANGE COMMISSION. THESE SECURITIES MAY NOT BE SOLD NOR
     MAY OFFERS TO BUY BE ACCEPTED PRIOR TO THE TIME THE REGISTRATION STATEMENT
     BECOMES EFFECTIVE. THIS PROSPECTUS SHALL NOT CONSTITUTE AN OFFER TO SELL OR
     THE SOLICITATION OF AN OFFER TO BUY NOR SHALL THERE BE ANY SALE OF THESE
     SECURITIES IN ANY STATE IN WHICH SUCH OFFER, SOLICITATION OR SALE WOULD BE
     UNLAWFUL PRIOR TO REGISTRATION OR QUALIFICATION UNDER THE SECURITIES LAWS
     OF ANY SUCH STATE.
 
                             SUBJECT TO COMPLETION
                  PRELIMINARY PROSPECTUS DATED MARCH 18, 1996
 
                                1,350,000 SHARES
(LOGO)
 
                            ADVANCED MAGNETICS, INC.
                                  COMMON STOCK
 
                            ------------------------
 
     Of the 1,350,000 shares of Common Stock offered hereby, 1,100,000 shares
are being offered by Advanced Magnetics, Inc. and 250,000 shares are being
offered by certain stockholders of the Company (the "Selling Stockholders"). The
Company will not receive any proceeds from the sale of shares by the Selling
Stockholders. See "Principal and Selling Stockholders."
 
     The Common Stock is traded on the American Stock Exchange under the symbol
AVM. On March 14, 1996, the closing sale price of the Common Stock was $23.38
per share. See "Price Range of Common Stock and Dividend Policy."
 
      THESE SECURITIES INVOLVE A HIGH DEGREE OF RISK. SEE "RISK FACTORS" AT PAGE
6.
                            ------------------------
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE
    SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES
      COMMISSION NOR HAS THE SECURITIES AND EXCHANGE COMMISSION OR
        ANY STATE SECURITIES COMMISSION PASSED UPON THE ACCURACY
          OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO
                       THE CONTRARY IS A CRIMINAL OFFENSE.
 

<TABLE>
- ------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------
<CAPTION>
                                                     Underwriting                   Proceeds to
                                        Price to     Discounts and   Proceeds to      Selling
                                         Public      Commissions(1)  Company(2)    Stockholders
<S>                                   <C>            <C>            <C>            <C>
- ------------------------------------------------------------------------------------------------
Per Share...........................  $              $              $              $
- ------------------------------------------------------------------------------------------------
Total...............................  $              $              $              $
- ------------------------------------------------------------------------------------------------
Total Assuming Full Exercise of
  Over-Allotment Option(3)..........  $              $              $              $
- ------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------
<FN> 
(1) See "Underwriting."
(2) Before deducting expenses estimated at $450,000, which are payable by the
    Company.
(3) Assuming exercise in full of a 30-day option granted by the Company to the
    Underwriters to purchase up to 202,500 additional shares of Common Stock, on
    the same terms, solely to cover over-allotments. See "Underwriting."
</TABLE>

                            ------------------------
 
     The shares of Common Stock are offered by the Underwriters, subject to
prior sale, when, as and if delivered to and accepted by the Underwriters, and
subject to their right to reject orders in whole or in part. It is expected that
delivery of the Common Stock will be made in New York City on or about March   ,
1996.
                            ------------------------
 
PAINEWEBBER INCORPORATED
 
                     DONALDSON, LUFKIN & JENRETTE
                        SECURITIES CORPORATION

                                         OPPENHEIMER & CO., INC.
 
                                                       TUCKER ANTHONY
                                                        INCORPORATED
                            ------------------------
 
                 THE DATE OF THIS PROSPECTUS IS MARCH   , 1996.

<PAGE>   3
 
                                 
[PICTURE]       Fifty year old male with hepatocellular carcinoma.
                MRI scan without Feridex I.V. (top).  After admin-
                istration of Feridex I.V. (bottom), the normal liver
                appears dark while an approximately 15mm lesion 
                appears bright.
 



[PICTURE] A                                     [PICTURE] B

Forty-three year old female with cancer of the external auditory canal and
suspected metastasis to the lymph nodes.  MRI study without Combidex (A) shows
a large lymph node in the neck.  MRI scan of the neck 24 hours after
administration of Combidex (B) indicates a metastatic tumor.  Post surgery
analysis confirmed the presence of metastatic disease.

                               ---------------

        IN CONNECTION WITH THIS OFFERING, THE UNDERWRITERS MAY OVER-ALLOT OR
EFFECT TRANSACTIONS WHICH STABILIZE OR MAINTAIN THE MARKET PRICE OF THE COMMON
STOCK OF THE COMPANY AT A LEVEL ABOVE THAT WHICH MIGHT OTHERWISE PREVAIL IN THE
OPEN MARKET. SUCH TRANSACTIONS MAY BE EFFECTED ON THE AMERICAN STOCK EXCHANGE
OR OTHERWISE. SUCH STABILIZING, IF COMMENCED, MAY BE DISCONTINUED AT ANY TIME.

<PAGE>   4
 
                            AVAILABLE INFORMATION
 
        The Company is subject to the informational requirements of the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), and, in
accordance therewith, files reports, proxy and information statements and other
information with the Securities and Exchange Commission (the "Commission").
Reports, proxy and information statements filed by the Company with the
Commission pursuant to the informational requirements of the Exchange Act may
be inspected and copied at the public reference facilities maintained by the
Commission at Room 1024, Judiciary Plaza, 450 Fifth Street, N.W., Washington,
D.C. 20549, and at the Commission's Regional Offices at 7 World Trade Center,
13th Floor, New York, New York 10048 and Northwestern Atrium Center, 500 West
Madison Street, Suite 1400, Chicago, Illinois 60661-2511. Copies of such
material can also be obtained from the Public Reference Section of the
Commission at Room 1024, Judiciary Plaza, 450 Fifth Street N.W., Washington,
D.C. 20549 at prescribed rates. In addition, reports, proxy statements and
other information concerning the Company (symbol: AVM) can be inspected and
copied at the American Stock Exchange, 86 Trinity Place, New York, New York
10006.
 
        The Company has filed with the Commission a Registration Statement on
Form S-3 (the "Registration Statement," which term shall include all
amendments, exhibits, annexes and schedules thereto), under the Securities Act
of 1933, as amended (the "Securities Act"), with respect to the Common Stock
offered hereby. This Prospectus does not contain all of the information set
forth in the Registration Statement and the exhibits and schedules thereto,
certain parts of which are omitted in accordance with the rules and regulations
of the Commission. Copies of the Registration Statement, including all exhibits
thereto, may be obtained from the Commission's principal office in Washington
D.C. upon payment of the fees prescribed by the Commission or may be examined
without charge at the offices of the Commission as described above.
 
               INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
        The following documents, heretofore filed by the Company with the
Commission pursuant to the Exchange Act, are incorporated by reference in this
Prospectus:
 
        (i) Annual Report on Form 10-K for the fiscal year ended September 30,
1995;
 
        (ii) Proxy Statement of the Company dated December 28, 1995 for its
Annual Meeting of Stockholders held on February 6, 1996;
 
        (iii) Quarterly Report on Form 10-Q for the fiscal quarter ended
December 31, 1995; and
 
        (iv) the description of the Company's Common Stock contained in the
Company's Registration Statement on Form 8-A.
 
        Each document filed by the Company pursuant to Section 13(a), 13(c), 14
or 15(d) of the Exchange Act prior to the termination of the offering of the
shares of Common Stock shall be deemed to be incorporated by reference in this
Prospectus and to be a part hereof from the date of filing of such documents.
The Company will provide without charge to each person, including any
beneficial owner, to whom a copy of this Prospectus is delivered, upon the
written or oral request of any such person, a copy of any document (other than
exhibits). Requests for such copies should be directed to Marlene Goldstein,
Advanced Magnetics, Inc., 61 Mooney Street, Cambridge, MA 02138; telephone
(617) 497-2070.
 
        Any statement contained herein or in a document incorporated or deemed
to be incorporated herein by reference shall be deemed to be modified or
superseded for purposes of this Prospectus to the extent that a statement
contained herein or in any subsequently filed document that is incorporated by
reference herein modifies or supersedes such statement. Any such statement so
modified or superseded shall not be deemed, except as so modified or
superseded, to constitute a part of this Prospectus.
 
        Feridex I.V.[TM] and Combidex[TM] are trademarks of the Company.
GastroMARK[R] is a registered trademark of Mallinckrodt Medical, Inc.
Endorem[TM], Sinerem[TM] and Lumirem[TM] are trademarks of Guerbet, S.A. and
are registered in France and other jurisdictions. This Prospectus also includes
trade names, trademarks and registered trademarks of other companies.
 
                                      2

<PAGE>   5
 
                              PROSPECTUS SUMMARY
 
        The following summary is qualified in its entirety by the more detailed
information and financial statements appearing elsewhere in this Prospectus.
Unless otherwise indicated, the information in this Prospectus assumes that the
Underwriters' over-allotment option will not be exercised. Investors should
carefully consider the information set forth under the heading "Risk Factors."
Certain of the information contained in this summary and elsewhere in this
Prospectus are forward-looking statements which involve risks and
uncertainties. The Company's actual results may differ significantly from the
results discussed in the forward-looking statements. Factors that might cause
such a difference include, but are not limited to, those discussed under "Risk
Factors."
 
                                 THE COMPANY
 
        Advanced Magnetics develops, manufactures and markets organ-specific
contrast agents to improve the diagnostic capabilities of soft tissue magnetic
resonance imaging ("MRI") scans and is developing a drug delivery platform that
targets therapeutics to the liver for the treatment of certain liver diseases.
The Company is a leader in the development of organ-specific superparamagnetic
MRI contrast agents, including Feridex I.V. for the liver, GastroMARK for the
gastrointestinal system, and Combidex for the liver, spleen, lymphatic system
and blood flow. Sales of Feridex I.V. have commenced in Europe, and the Company
recently received an approvable letter from the U.S. Food and Drug
Administration ("FDA") for this product. GastroMARK has been approved for
marketing in several European countries and Canada, and a New Drug Application
("NDA") for this product was submitted to the FDA in November 1993. With
respect to Combidex, the Company and its collaborative partner in Europe,
Guerbet, S.A. ("Guerbet"), have completed Phase II clinical trials in both the
United States and Europe for several indications. The Company has completed
patient enrollment for Phase III trials for Combidex in the United States for
imaging liver lesions and expects to begin separate Phase III trials in 1996
for Combidex as a blood flow contrast agent in magnetic resonance angiography
("MRA"), a form of MRI that assesses blood flow obstructions or constrictions.
In 1996, the Company and Guerbet expect to begin Phase III trials for Combidex
in the United States and Europe for imaging of lymph nodes. In addition to
these contrast agents, Advanced Magnetics is applying its organ-specific
technology and expertise to the development of a drug delivery platform
targeting therapeutics to the liver and expects to commence clinical trials in
Europe for a treatment of hepatitis B in 1996.
 
        MRI is a diagnostic imaging technique that is used to identify internal
abnormalities and changes in structure. Contrast agents increase the usefulness
of MRI by allowing radiologists to differentiate structures and organs with
greater diagnostic confidence. The Company believes that MRI scans produced
with contrast agents are clearer and permit the identification of smaller
abnormalities than images produced by MRI without contrast agents or contrast
enhanced computerized tomography ("CECT"). MRI contrast agents frequently allow
for more accurate diagnosis and monitoring of treatment results and may be a
cost-effective way to optimize medical treatments and to improve patient
outcomes. Currently, the primary use of MRI is for studies of the central
nervous system, which accounted for approximately 74% of the estimated 7.4
million MRI studies performed in the United States in 1994. Approximately 29%
of these MRI studies were contrast enhanced at a cost to payors of
approximately $145 million for contrast agents. The Company believes that the
development of effective contrast agents will increase the use of MRI as a
diagnostic imaging technique and will allow MRI to be used for a wider range of
applications, in turn generating additional demand for MRI contrast agents.
 
        No MRI contrast agents designed specifically for the liver or the
lymphatic system are currently being marketed anywhere in the world, except for
the Company's Feridex I.V. liver agent, which is being sold in Europe. The
liver and the lymphatic system are among the principal sites for metastasis of
many common cancers (including colon, prostate and breast cancer) originating
in other parts of the body. CECT is currently the primary imaging technique
used to confirm a preliminary or suspected diagnosis of liver cancer, and the
Company believes that approximately 1.75 million CECT liver scans were
performed in the United States in 1995 at an estimated contrast agent cost of
over $100 million. With respect to the lymphatic system, there currently are no
effective imaging techniques. An MRI contrast agent that localizes to and
causes contrast
 
                                      3

<PAGE>   6
 
enhancement of the lymph nodes, such as Combidex, could allow for more accurate
disease diagnosis and monitoring of treatment results. The Company believes that
GastroMARK, because it enhances the contrast between the bowel and other
abdominal structures, will increase the use of MRI as an imaging technology for
the abdomen. In light of these potential applications of MRI contrast agents,
the Company believes that it is well positioned to benefit from the expected
demand for such agents and to capture a portion of the over $3 billion worldwide
market for imaging agents, approximately $294 million of which was associated
with MRI in 1995.
 
        In order to facilitate the marketing and distribution of its contrast
agents, the Company has entered into strategic relationships with certain
established pharmaceutical companies. These relationships, both in the United
States and abroad, include: (i) Guerbet, a leading European producer of
contrast agents, in Western Europe and Brazil; (ii) Eiken Chemical Co., Ltd.
("Eiken"), one of Japan's leading medical diagnostics manufacturers, in Japan;
(iii) Berlex Laboratories, Inc., division of Schering A.G. of Germany
("Berlex"), the leading marketer in the United States of MRI contrast agents,
in the United States; and (iv) Mallinckrodt Medical, Inc. ("Mallinckrodt"), a
leading manufacturer in the United States of contrast agents, in the United
States, Canada and Mexico.
 
        The Company's expertise in organ-specific technology provides it with
biopharmaceutical opportunities beyond its core MRI contrast agent products.
Advanced Magnetics is developing a drug delivery platform that targets
therapeutics to the liver. The Company believes that arabinogalactan, a
naturally occurring polysaccharide that binds to the asialoglycoprotein ("ASG")
receptor found in abundance on hepatocytes, the principal cells comprising the
liver, has commercial promise in drug delivery. Arabinogalactan was initially
developed by the Company as a delivery agent for targeting contrast agents to
the liver because of its high specificity, low cost and lack of toxicity. The
Company is currently focusing on the development of a product for the treatment
of hepatitis B consisting of a conjugate of arabinogalactan and vidarabine
monophosphate ("AraAMP"). Vidarabine ("AraA") is an existing therapeutic agent
that has shown efficacy in the treatment of hepatitis B, but is unacceptably
toxic when used in an unconjugated form. Clinical trials for this product
candidate are expected to begin in 1996 in Europe. Advanced Magnetics intends
to study the efficacy of other therapeutic agents combined with arabinogalactan
for the treatment of hepatitis C, hepatitis D and liver cancer.
 
        The Company was incorporated in Delaware in 1981. The Company's
principal executive offices are located at 725 Concord Avenue, Cambridge,
Massachusetts 02138, and its telephone number is (617) 354-3929.


<TABLE>
 
                                 THE OFFERING

<S>                                      <C>
Common Stock Offered by the Company....  1,100,000 shares of Common Stock, par 
                                         value $.01 per share (the "Common 
                                         Stock")
Common Stock Offered by the Selling
  Stockholders.........................  250,000 shares

Common Stock to be Outstanding after
  the Offering.........................  7,866,642 shares(1)

Use of Proceeds........................  To fund research and development, 
                                         clinical trials, working capital, 
                                         potential acquisitions and general 
                                         corporate purposes. See "Use of 
                                         Proceeds."

American Stock Exchange symbol.........  AVM

<FN> 
- ---------------
(1) Based on the number of shares outstanding at March 14, 1996. Excludes an
    aggregate of 416,250 shares of Common Stock issuable pursuant to outstanding
    stock options on that date.

</TABLE>

 
                                      4

<PAGE>   7
 

<TABLE>
                                                   SUMMARY FINANCIAL INFORMATION
                                             (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
 
<CAPTION>
                                                                                                         THREE MONTHS
                                                                 YEAR ENDED SEPTEMBER 30,             ENDED DECEMBER 31,
                                                            ----------------------------------       --------------------
                                                             1993          1994         1995          1994         1995
                                                            -------       ------       -------       ------       -------
<S>                                                         <C>           <C>          <C>           <C>          <C>
STATEMENT OF OPERATIONS DATA:
  Revenues:
    License fees..........................................  $ 1,010       $5,505       $ 5,000       $   --       $    --
    Royalties.............................................      906           16           189           --            75
    Product sales.........................................    3,836          281         2,120           55            --
    Contract research and development.....................      403           --            --           --            --
    Interest, dividends and net gains and losses on sales
      of securities.......................................    2,823        1,845         2,287          682           452
                                                            -------       ------       -------       ------       -------
      Total revenues(1)...................................    8,978        7,647         9,596          737           527
  Costs and expenses:
    Cost of product sales.................................    1,526           55           425           11            --
    Contract research and development expenses............      193           --            --           --            --
    Company-sponsored research and development expenses...    6,863        6,622         8,602        1,598         2,161
    Charge (credit) for purchase of in-process research
      and development(2)..................................       --          760          (380)        (380)           --
    Selling, general and administrative expenses..........    2,778        1,964         1,759          316           291
                                                            -------       ------       -------       ------       -------
      Total costs and expenses............................   11,360        9,401        10,406        1,545         2,452
  Other income:
    Gain on sale of in vitro product line(1)..............       --        2,650         3,405           --            --
                                                            -------       ------       -------       ------       -------
  Income (loss) before provision for income taxes and
    cumulative effect of accounting change................   (2,382)         896         2,595         (808)       (1,925)
  Income tax provision....................................       --            8           400           --            --
                                                            -------       ------       -------       ------       -------
  Income (loss) before cumulative effect of accounting
    change................................................   (2,382)         888         2,195         (808)       (1,925)
  Cumulative effect of accounting change(3)...............       --           --           118          118            --
                                                            -------       ------       -------       ------       -------
  Net income (loss).......................................  $(2,382)      $  888       $ 2,313       $ (690)      $(1,925)
                                                            =======       ======       =======       ======       =======
  Net income (loss) per share before cumulative effect of
    accounting change.....................................  $ (0.36)      $ 0.13       $  0.32       $(0.12)      $ (0.28)
  Cumulative effect of accounting change(3)...............       --           --          0.02         0.02            --
                                                            -------       ------       -------       ------       -------
  Income (loss) per share.................................  $ (0.36)      $ 0.13       $  0.34       $(0.10)      $ (0.28)
                                                            =======       ======       =======       ======       =======
  Weighted average number of common and common equivalent
    shares................................................    6,651        6,807         6,871        6,718         6,756
</TABLE>

 

<TABLE>
<CAPTION>
                                                                                              DECEMBER 31, 1995
                                                                                          --------------------------
                                                                                          ACTUAL      AS ADJUSTED(4)
                                                                                          -------     --------------
<S>                                                                                       <C>             <C>
BALANCE SHEET DATA:
  Cash and cash equivalents.............................................................  $ 2,526         $26,246
  Marketable securities.................................................................   37,691          37,691
  Working capital.......................................................................   40,386          64,106
  Total assets..........................................................................   48,715          72,435
  Stockholders' equity..................................................................   47,390          71,110
<FN> 
- ---------------
(1) On October 15, 1993, the Company sold its in vitro product line to PerSeptive Biosystems, Inc. and recorded a 
    $2,650,000 gain on the sale. The sale also included a contingent earn-out based on 1995 revenues which resulted in a 
    $3,405,000 gain in 1995. Exclusive of the in vitro product line revenues, 1993 total revenues would have been $3,961,000 
    consisting of license fees of $1,000,000, contract research and development revenues of $138,000, and total interest, 
    dividends and net gains and losses on sales of securities of $2,823,000.
 
(2) In August 1994, the Company reacquired the development and marketing rights to the MRI contrast agent Combidex previously 
    licensed to Squibb Diagnostics, a division of Bristol-Myers Squibb Co., and recorded a related $760,000 charge for the 
    purchase of in-process research and development. In the first fiscal quarter of 1995, a credit for $380,000 was recorded 
    to the purchase of in-process research and development as a result of an amendment of the agreement between the Company 
    and Squibb. See "Management's Discussion and Analysis of Financial Condition and Results of Operations" and the Company's 
    financial statements and notes thereto appearing elsewhere in this Prospectus.
 
(3) In the first quarter of fiscal 1995, the Company adopted Statement of Financial Accounting Standards No. 115, "Accounting 
    for Certain Investments in Debt and Equity Securities," which requires that marketable securities classified as available 
    for sale be recorded at fair market value, and recorded a cumulative change of $118,000.
 
(4) Adjusted to reflect the sale by the Company of 1,100,000 shares of Common Stock offered hereby, at an assumed offering 
    price of $23.38 per share (the closing price on March 14, 1996) and the application of the net proceeds therefrom. See 
    "Use of Proceeds."
</TABLE>

 
                                       5

<PAGE>   8
 
                                 RISK FACTORS
 
        In addition to the other information in this Prospectus, prospective
investors should consider carefully the following risk factors in evaluating
the Company and its business before purchasing shares of the Common Stock
offered hereby.
 
EARLY STAGE OF PRODUCT COMMERCIALIZATION; UNCERTAINTY OF PRODUCT DEVELOPMENT
 
        The Company has not generated significant revenues from the sale of its
products. None of the Company's products have been approved for sale in the
United States, and the sale of Feridex I.V. and GastroMARK has only recently
begun in certain European countries. While the Company is conducting human
clinical testing of Combidex, this product and the Company's other product
candidates, in particular its targeted therapeutic products, will require
significant additional research and development efforts, including extensive
human clinical testing, prior to submission of any regulatory application for
commercial sale of such products. Such products are not expected to be
commercially available for several years, if at all. The development of new
pharmaceutical products is highly uncertain and no assurance can be given that
any of the Company's development programs will be completed successfully, that
required regulatory approvals will be obtained on a timely basis, if at all, or
that any product, including Feridex I.V., will be commercially successful.
 
        The Company's long-term viability and growth will depend on the
successful commercialization of products resulting from its research
activities. If any of the Company's development programs are not completed
successfully, required regulatory approvals are not obtained or products for
which approvals are obtained are not commercially successful, the Company's
business, financial condition and results of operations could be materially
adversely affected. See "Business -- Products under Development."
 
NEED FOR FUTURE FUNDING; UNCERTAINTY OF ACCESS TO CAPITAL
 
        The Company has expended and will continue to expend substantial funds
to complete the research, development, clinical trials, regulatory approvals
and other activities through final commercialization of its products. The
Company's future capital requirements will depend on many factors, including
market acceptance of the Company's products, continued scientific progress in
its research and development programs, the magnitude of these programs,
progress with preclinical testing and clinical trials, the time and costs
involved in obtaining regulatory approvals, the costs involved in filing,
prosecuting and enforcing patent claims, competing technological and market
developments, the cost of commercialization activities and arrangements and the
cost of product in-licensing and any possible acquisitions. It is possible that
the Company may need additional financing to satisfy its capital and operating
requirements relating to the development, manufacturing and marketing of its
contrast agents. If the Company were to incur the costs associated with
research, development, clinical trials, regulatory approvals and other
activities through final commercialization of the Company's targeted
therapeutic products, it would require additional outside funding. The Company
may seek such financing through arrangements with collaborative partners and
through public or private sales of the Company's securities, including equity
securities. No assurance can be given that such financing will be available to
the Company on acceptable terms, if at all. Any additional equity financings
could be dilutive to the Company's stockholders. If adequate additional funds
are not available, the Company may be required to curtail significantly one or
more of its research and development programs or obtain funds through
arrangements with collaborative partners or others that may require the Company
to relinquish rights to certain of its products and product candidates on terms
that it might otherwise find unacceptable. See "Management's Discussion and
Analysis of Financial Condition and Results of Operations."
 
GOVERNMENT REGULATION; NO ASSURANCE OF REGULATORY APPROVAL
 
        The Company's research and preclinical testing and clinical trials of
its product candidates and the manufacturing and marketing of its products are
subject to extensive and rigorous regulation by numerous governmental
authorities in the United States and in other countries where the Company
intends to test and
 
                                      6

<PAGE>   9
 
market its product candidates and products. Prior to marketing, any product
candidate must undergo an extensive regulatory approval process, which includes
preclinical testing and clinical trials of such product candidate to demonstrate
safety and efficacy. This regulatory process can require many years and the
expenditure of substantial resources. Data obtained from preclinical testing and
clinical trials are subject to varying interpretations, which can delay, limit
or prevent FDA approval. In addition, changes in FDA approval policies or
requirements may occur or new regulations may be promulgated which may result in
delay or failure to receive FDA approval. Similar delays or failures may be
encountered in foreign countries. Delays and related costs in obtaining
regulatory approvals could have a material adverse effect on the Company's
business, financial condition and results of operations. Although the Company
has received an approvable letter from the FDA for Feridex I.V. and has received
regulatory approval in certain foreign countries for the marketing of Feridex
I.V. and GastroMARK, there can be no assurance that further regulatory approvals
will be obtained for any products developed by the Company. Failure to obtain
requisite governmental approvals or failure to obtain approvals of the scope
requested could delay and may preclude the Company or its licensees or other
collaborators from marketing the Company's products or limit the commercial use
of the products and could have a material adverse effect on the Company's
business, financial condition and results of operations.
 
     Regulatory approvals may entail limitations on the indicated uses of such
products and impose labeling requirements which may adversely impact the
Company's ability to market its products. Even if regulatory approval is
obtained, a marketed product and its manufacturer are subject to continuing
regulatory review. Consequently, discovery of previously unknown problems with a
product or manufacturer may have certain adverse effects, including withdrawal
of the product from the market. Noncompliance with regulatory requirements of
the approval process at any stage, including preclinical testing and clinical
trials, or post-approval, may result in various adverse consequences, including
the FDA's delay in approving or its refusal to approve a product, withdrawal of
an approved product from the market or, under certain circumstances, the
imposition of criminal penalties. Any such adverse consequences could have a
material adverse effect on the Company's business, financial condition and
results of operations. See "Business -- Government Regulation and
Reimbursement."
 
UNCERTAINTIES RELATING TO CLINICAL TRIALS; TECHNOLOGICAL UNCERTAINTY
 
     Before obtaining regulatory approvals for the commercial sale of any of its
contrast agents or other product candidates, the Company must demonstrate
through extensive preclinical testing and human clinical trials that the product
is safe and efficacious. In addition to ongoing clinical trials of Combidex, the
Company intends to commence clinical trials in humans of its targeted
therapeutic product for the treatment of hepatitis B in 1996. The results from
preclinical testing and early clinical trials of these and other products under
development by the Company may not be predictive of results obtained in
subsequent clinical trials. A number of companies in the pharmaceutical and
biopharmaceutical industries have suffered significant setbacks in advanced
clinical trials, even after obtaining promising results in earlier trials. In
addition, clinical trials are often conducted with patients in the most advanced
stages of disease. During the course of treatment, these patients can die or
suffer adverse medical effects for reasons that may not be related to the
product being tested, but which can nevertheless adversely affect clinical trial
results or approvals by the FDA. Clinical testing of a pharmaceutical product is
itself subject to approvals by various governmental regulatory authorities.
There can be no assurance that Advanced Magnetics will be permitted by
regulatory authorities to commence or continue clinical trials or if such trials
are conducted, that any of the Company's potential products will prove safe and
efficacious or will receive regulatory approvals in the United States or abroad.
Any delays in or termination of the Company's clinical trial efforts could have
a material adverse effect on the Company's business, financial condition and
results of operations. See "Business -- Government Regulation and
Reimbursement."
 
     Many of the Company's products are subject to technological uncertainty.
The FDA has not approved any of the Company's products for sale in the United
States and has not approved any contrast agent based on magnetic particles
developed by any party. Furthermore, the FDA has neither approved the use of
AraA or AraAMP for the treatment of hepatitis B nor has it approved the use of
arabinogalactan as a delivery agent.
 
                                        7

<PAGE>   10
 
There can be no assurance that the combination will receive regulatory approval
for the treatment of hepatitis B or any other condition or disease. In addition,
obtaining regulatory approval for products consisting of arabinogalactan
connected to AraAMP or any other therapeutic compound may be more difficult than
obtaining approval for a single compound because it could be more difficult to
determine the safety and efficacy of the two compounds together. Furthermore,
AraA has demonstrated unacceptable levels of toxicity when used in an
unconjugated form in clinical trials for the treatment of hepatitis. The
Company's MRI contrast agents may cause adverse reactions, including death, in
certain persons under certain conditions. There can be no assurances that these
factors will not adversely affect the development or commercialization of the
Company's products. See "Business -- Products under Development."
 
DEPENDENCE ON COLLABORATIVE RELATIONSHIPS
 
        The Company's strategy for the development and commercialization of its
contrast agent product candidates is to enter into strategic alliances with
various corporate partners, licensees and other collaborators. In some cases,
the Company is dependent upon these collaborators to conduct preclinical and
clinical testing, to obtain regulatory approvals and to manufacture and market
products. The amount and timing of resources that the collaborators devote to
these activities is not within the control of the Company, and certain of the
Company's corporate partners are developing products which, if commercialized,
would compete with the Company's products and product candidates. There can be
no assurance that any revenues or profits will be derived from such
relationships, that any of the Company's current collaborative relationships
will be continued or that the Company will be able to enter into future
collaborative relationships. If any of the Company's collaborators breaches its
agreement with the Company or otherwise fails to perform, such event could have
a material adverse effect on the Company's business, financial condition and
results of operations. See "Business -- Licensing and Marketing Arrangements."
 
COMPETITION AND RISK OF TECHNOLOGICAL OBSOLESCENCE
 
        The pharmaceutical and biopharmaceutical industries are subject to
intense competition and rapid technological change. The Company has many
competitors, including pharmaceutical, biotechnology and chemical companies, a
number of which, including certain of its corporate partners, are actively
developing and marketing products that if commercialized would compete with the
Company's products and product candidates. Many of these competitors have
substantially greater capital and other resources than the Company and
represent significant competition for Advanced Magnetics. Such companies may
succeed in developing technologies and products that are more effective or less
costly than any that may be developed by the Company, and such companies may be
more successful than the Company in developing, manufacturing and marketing
products. In addition, the Company's MRI contrast agents represent a new
approach to imaging certain organs, and market acceptance of both MRI as an
appropriate imaging technique for such organs and the Company's products is
critical to the Company's ability to compete successfully. There can be no
assurance that the Company will be able to compete successfully in the future
or that developments by others will not render the Company's products or
product candidates or technologies obsolete or noncompetitive or that the
Company's collaborators or customers will not choose to use competing
technologies or products. See "Business -- Competition."
 
UNCERTAINTY REGARDING PATENTS AND PROPRIETARY RIGHTS
 
        The Company's success will be dependent, in part, on its ability to
obtain patent protection for its product candidates, maintain trade secret
protection, prevent third parties from infringing upon its proprietary rights
and operate without infringing upon the proprietary rights of others, both in
the United States and abroad.
 
        The patent positions of pharmaceutical and biopharmaceutical firms,
including Advanced Magnetics, are generally uncertain and involve complex legal
and factual questions. Because of the substantial length of time and expense
associated with bringing new products through development and regulatory
approval to the marketplace, the pharmaceutical and biopharmaceutical
industries place considerable importance on obtaining patent and trade secret
protection for new technologies, products and processes. There can be no
assurance as to the success or timeliness in obtaining any such patents, that
the breadth of the claims obtained
 
                                      8

<PAGE>   11
 
will provide any significant protection of the Company's technology, or that the
degree of protection afforded by patents for licensed technologies or for future
discoveries will be adequate to protect the Company's proprietary technology.
Moreover, no assurance can be given that patents issued to Advanced Magnetics
will not be contested, invalidated or circumvented. One of the Company's MRI
patents is the subject of two interference proceedings in the U.S. Patent
Office. The Company has a non-exclusive license to the patent applications
involved in one of these interference proceedings, which applications are owned
by Nycomed Imaging A.S. of Oslo, Norway ("Nycomed") and Schering A.G. of Germany
("Schering"). Because the Company does not currently have rights in all the
patents and patent applications which are the subject of the other interference,
there can be no assurance that the outcome of that interference will not have an
outcome with a material adverse effect on the Company. There can be no assurance
that future patent interferences involving patents of either the Company or its
licensors will not have a material adverse effect on the Company's business.
Moreover, there can be no assurance that claims of infringement or violation of
the proprietary rights of others will not be asserted against the Company. If
Advanced Magnetics is required to defend against such claims or to protect its
own proprietary rights against others, the Company may incur substantial costs
which could have a material adverse effect on the Company's business, financial
condition and results of operations.
 
        In the future, Advanced Magnetics may be required to obtain additional
licenses to patents or other proprietary rights of others. There can be no
assurance that any such licenses will be available on acceptable terms, if at
all. The failure to obtain such licenses could result in delays in marketing
the Company's products or the inability to proceed with the development,
manufacturing or sale of product candidates requiring such licenses. In
addition, the termination of any of the Company's existing licensing
arrangements could have a material adverse effect on the Company's business,
financial condition and results of operations.
 
        The Company also relies upon unpatented trade secrets and improvements,
unpatented know-how and continuing technological innovation to develop and
maintain its competitive position, which it seeks to protect, in part, by
confidentiality agreements with its corporate partners, collaborators,
employees and consultants. There can be no assurance that these agreements will
not be breached, that the Company will have adequate remedies for any such
breach or that the Company's trade secrets will not otherwise become known or
be independently discovered by its competitors. In addition, the Company cannot
be certain that others will not independently develop substantially equivalent
or superseding proprietary technology, or that an equivalent product will not
be marketed in competition with the Company's products, thereby substantially
reducing the value of the Company's proprietary rights. See "Business --
Patents and Trade Secrets."
 
UNCERTAINTY OF THIRD-PARTY REIMBURSEMENT
 
        In both the United States and foreign markets, the Company's ability to
commercialize its products may depend in part on the extent to which
reimbursement for the costs of such products and related treatments will be
available from government health administration authorities, private health
insurers and other third-party payors. In the United States, there has been,
and the Company expects that there will continue to be, a number of federal and
state proposals to reform the health care system. In addition, an increasing
emphasis on managed care in the United States has and will continue to put
pressure on pharmaceutical pricing. Such initiatives and proposals, if adopted,
could decrease the price that the Company receives for its existing products,
as well as any products it may develop and sell in the future. Significant
uncertainty exists as to the reimbursement status of both newly approved health
care products and products used for indications not approved by the FDA. If
adequate reimbursement levels are not maintained by government and other third-
party payors for the Company's products and related treatments, the Company's
business, financial condition and results of operations may be materially
adversely affected. See "Business -- Government Regulation and Reimbursement."
 
LIMITED MANUFACTURING EXPERIENCE AND CAPACITY
 
        Advanced Magnetics has no experience in manufacturing targeted
therapeutic products and limited experience in manufacturing contrast agents in
commercial quantities. Currently, the Company manufactures bulk Feridex I.V.
product for sale by Guerbet, and has developed the necessary capabilities to
manufacture
 
                                      9

<PAGE>   12
 
Feridex I.V. finished product and GastroMARK bulk product in its Massachusetts
facilities. These facilities are subject to current Good Manufacturing Practices
("GMP") regulations prescribed by the FDA. There can be no assurance that the
Company will be able to continue to operate at commercial scale in compliance
with the GMP regulations. Failure to operate in compliance with such GMP
regulations and other applicable manufacturing requirements of various
regulatory agencies could have a material adverse effect on the Company's
business, financial condition and results of operations. See "Business --
Government Regulation and Reimbursement." In addition, the Company is dependent
on contract manufacturers for the production of certain of its product
candidates. In the event that the Company is unable to obtain or retain
manufacturing for its product candidates, it will not be able to develop and
commercialize its products as planned. There can be no assurance that the
Company will be able to enter into agreements for the manufacture of future
products with manufacturers whose facilities and procedures comply with GMP and
other regulatory requirements or that such manufacturer will be able to deliver
required quantities of product that conform to specifications in a timely
manner. See "Business -- Manufacturing."
 
LACK OF MARKETING AND SALES HISTORY
 
        Advanced Magnetics has no experience in marketing and selling its
current products and product candidates and relies on its corporate partners to
market and sell certain products. In order to achieve commercial success for
any product candidate approved by the FDA for which the Company does not have a
marketing partner, Advanced Magnetics may have to enlarge and expand its
marketing and sales force or enter into arrangements with others to market and
sell its products. There can be no assurance that Advanced Magnetics will be
successful in attracting and retaining qualified marketing and sales personnel
or that it will be able to enter into marketing and sales agreements with
others on acceptable terms, if at all. Furthermore, there can be no assurance
that Advanced Magnetics or its corporate partners will be successful in
marketing and selling the Company's products. See "Business -- Licensing and
Marketing Arrangements."
 
POTENTIAL PRODUCT LIABILITY; UNCERTAINTIES RELATED TO INSURANCE
 
        The use of any of the Company's product candidates in clinical trials
and the sale of any approved products may expose the Company to liability
claims resulting from the use of products or product candidates. These claims
might be made directly by customers (including corporate partners), clinical
trial subjects, patients, pharmaceutical companies or others. The Company
maintains product liability insurance coverage for claims arising from the use
of its products in clinical trials. However, coverage is becoming increasingly
expensive and no assurance can be given that the Company will be able to
maintain insurance at a reasonable cost. Furthermore, there can be no assurance
that the Company's insurance will provide sufficient amounts to protect the
Company against losses due to liability that could have a material adverse
effect on the Company's business, financial condition and results of
operations. The Company does not presently maintain product liability insurance
covering the sale of its products and there can be no assurance that the
Company will be able to obtain commercially reasonable product liability
insurance for any product presently being marketed or for any product approved
for marketing in the future or that insurance coverage and the resources of the
Company would be sufficient to satisfy any liability resulting from product
liability claims. A product liability claim or series of claims brought against
the Company could have a material adverse effect on its business, financial
condition and results of operations, whether or not the plaintiffs in such
claims ultimately prevail. See "Business -- Product Liability Insurance."
 
ATTRACTION AND RETENTION OF KEY EMPLOYEES
 
        Because of the specialized nature of its business, Advanced Magnetics
is highly dependent on its ability to attract and retain qualified scientific
and technical personnel for the research and development activities conducted
or sponsored by the Company. Recruiting and retaining qualified scientific and
technical personnel to perform research and development work is critical to the
Company's success. In addition, the Company is substantially dependent upon
Jerome Goldstein, its Chairman of the Board, Chief Executive Officer and
President. The loss of Mr. Goldstein or other certain key executive officers
would be detrimental to the Company. Furthermore, the Company's anticipated
growth and expansion into areas and activities requiring additional expertise,
such as clinical testing, regulatory compliance, manufacturing and marketing,
will require the addition of new management personnel and the development of
additional expertise by existing
 
                                      10

<PAGE>   13
 
management personnel. There is intense competition for qualified personnel in
the areas of the Company's activities, and there can be no assurance that the
Company will be able to continue to attract and retain the qualified personnel
necessary for the development of its business. The failure to attract and retain
such personnel or to develop such expertise could adversely affect the Company's
business, financial condition and results of operations.
 
HAZARDOUS MATERIALS
 
        The Company's manufacturing and research and development activities
involve the controlled use of hazardous materials, chemicals and various
radioactive compounds. Although the Company believes that its safety procedures
for handling and disposing of hazardous materials comply with the standards
prescribed by state and federal regulations, the risk of accidental
contamination or injury from these materials cannot be completely eliminated.
In the event of an accident, the Company could be held liable for any resulting
damages or fines and such liability could have a material adverse effect on the
Company's business, financial condition and results of operations.
 
CONCENTRATION OF OWNERSHIP
 
        Following completion of the Offering, directors, executive officers and
principal stockholders of the Company, and certain of their affiliates, will
beneficially own approximately 31% of the Company's outstanding Common Stock.
Accordingly, these stockholders, individually and as a group, may be able to
determine the outcome of stockholder votes, including votes concerning the
election of directors, the adoption or amendment of provisions in the Company's
Certificate of Incorporation or By-laws, and the approval of certain mergers
and other significant corporate transactions. Such control by existing
stockholders could have the effect of delaying, deferring or preventing a
change in control of the Company. There can be no assurance that these
individuals' ability to prevent or cause a change in control of the Company
will not have a material adverse effect on the market price of the Common
Stock.
 
FUTURE SALES OF COMMON STOCK BY CERTAIN STOCKHOLDERS; POTENTIAL ADVERSE EFFECT
ON MARKET PRICE OF COMMON STOCK
 
        As of March 14, 1996, 229,450 shares of Common Stock were issuable upon
the exercise of outstanding stock options. The executive officers and directors
of the Company, who together own or have the right to acquire an aggregate of
2,294,861 shares of Common Stock, have agreed that they will not (1) offer to
sell, contract to sell, sell, or otherwise dispose of any shares of Common
Stock or rights to acquire shares of Common Stock (other than pursuant to
employee stock option plans or in connection with other employee incentive
compensation arrangements) or (2) enter into any swap or similar agreement that
transfers, in whole or in part, any of the economic consequences of the
ownership of shares of Common Stock during the 90 day period following the date
of this Prospectus without the prior written consent of PaineWebber
Incorporated. The issuance of Common Stock upon the exercise of such stock
options, as well as future sales of such Common Stock or of shares of Common
Stock by existing stockholders, or the perception that such sales could occur
could adversely affect the market price of the Common Stock.
 
VOLATILITY OF COMMON STOCK PRICE
 
        The market prices for securities of biopharmaceutical and
pharmaceutical companies, including the Company, have historically been highly
volatile. Variations in revenues and expenses resulting from clinical trials,
additional licensing arrangements and timing of regulatory approvals and
royalty payments may continue to cause fluctuations in the Company's financial
performance from period to period. Such fluctuations in operating results may
cause the market price of the Company's Common Stock to be volatile. In
addition, the market prices for securities of biopharmaceutical and
pharmaceutical companies have from time to time experienced significant price
and volume fluctuations that are unrelated to the operating performance of such
companies. Various factors and events, including announcements by the Company
or its competitors concerning technological innovations, new products, clinical
trial results, agreements with collaborators, governmental regulations,
developments in patent or other proprietary rights, public concern regarding
the safety of drugs developed by the Company or others, may have a significant
impact on the market price of the Company's Common Stock and Dividend Policy.
See "Price Range of Common Stock."
 
                                      11

<PAGE>   14
 
                               USE OF PROCEEDS
 
        The net proceeds to be received by the Company from the sale of Common
Stock offered hereby (the "Offering") are estimated to be approximately
$23,720,000 ($28,169,000 if the Underwriters' over-allotment option is
exercised in full) assuming a public offering price of $23 3/8 per share and
after deducting estimated underwriting discounts and commissions and offering
expenses. The net proceeds of the Offering, together with the Company's
existing funds and cash generated from operations, are expected to be used for
the following purposes: (i) increased research and development; (ii) clinical
trials for its targeted therapeutic products; and (iii) working capital and
general corporate purposes. In addition, a portion of the proceeds may be used
to acquire companies and products that complement the business of the Company.
No such transactions are currently planned by the Company. The Company has in
the past and may in the future repurchase its securities in the open market
although it has no current plans to do so.
 
        The amounts actually expended for each of the above-referenced purposes
could vary significantly depending upon numerous factors, including the status
of the Company's research and development programs, clinical trials, regulatory
approvals, technological advances, determinations as to commercial potential,
any collaborative agreements entered into by the Company and competitive
developments. In addition, the Company's research and development expenditures
will vary as projects are added, extended or abandoned and as a result of
variations in funding from existing or future third party collaborators. Until
applied to any of the foregoing uses, the net proceeds of the Offering will be
invested by the Company in investment grade, interest bearing obligations.
 
        The Company will not receive any proceeds from the sale of Common Stock
by the Selling Stockholders. See "Principal and Selling Stockholders."
 
                                      12

<PAGE>   15
 
               PRICE RANGE OF COMMON STOCK AND DIVIDEND POLICY
 
        The Common Stock trades on the American Stock Exchange under the symbol
AVM. The following table sets forth for the periods indicated the high and low
sale prices for the Common Stock as reported by the American Stock Exchange.
 

<TABLE>
<CAPTION>
                                                               HIGH      LOW
                                                               ---       ---
<S>                                                            <C>       <C>
1994                                                        
  First Quarter..............................................  $14 1/8   $10 3/8
  Second Quarter.............................................   15 7/8    12
  Third Quarter..............................................   15        11 1/2
  Fourth Quarter.............................................   17 1/2    12 1/4
1995                                                        
  First Quarter..............................................   16 3/4    13 1/4
  Second Quarter.............................................   19 1/4    14 1/4
  Third Quarter..............................................   23 3/8    17 1/2
  Fourth Quarter.............................................   29        21
1996                                                        
  First Quarter (through March 14, 1996).....................   30        23 3/8
</TABLE>

 
        On March 14, 1996, the last reported sale price of the Common Stock on
the American Stock Exchange was $23 3/8 per share. As of March 13, 1996, there
were approximately 303 holders of record of the Common Stock.
 
        The Company has not declared any dividends on the Common Stock and does
not intend to declare any cash dividends on its Common Stock in the foreseeable
future. The Company currently intends to retain future earnings to fund the
development and growth of its business.
 
                                      13

<PAGE>   16

<TABLE>
 
                                CAPITALIZATION
 
        The following table sets forth the capitalization of the Company as of
December 31, 1995 and as adjusted to reflect the sale of the 1,100,000 shares
of Common Stock offered hereby and the application of net proceeds of
approximately $23,720,000. See "Use of Proceeds." This table should be read in
conjunction with the Company's audited financial statements and notes thereto
appearing elsewhere or incorporated by reference in this Prospectus.
 
<CAPTION>
                                                                                        DECEMBER 31, 1995
                                                                                    -------------------------
                                                                                    ACTUAL        AS ADJUSTED
                                                                                    ------        -----------
                                                                                         (IN THOUSANDS)
<S>                                                                                 <C>           <C>
Long-term debt....................................................................  $    --       $    --
                                                                                  
Stockholders' equity(1):                                                          
                                                                                  
  Preferred Stock, $.01 par value per share; 2,000,000 shares authorized, none    
     issued and outstanding.......................................................       --            --
                                                                                  
  Common Stock, $.01 par value per share; 15,000,000 shares authorized,           
     6,762,226 shares issued and outstanding, 7,862,226 shares issued             
     and outstanding as adjusted(1)...............................................       68            79
                                                                                  
  Additional paid-in-capital......................................................   45,164        68,873
                                                                                  
  Retained earnings...............................................................    1,112         1,112
                                                                                  
  Unrealized gain on marketable securities........................................    1,046         1,046
                                                                                    -------       -------
     Total stockholders' equity...................................................   47,390        71,110
                                                                                    -------       -------
       Total capitalization.......................................................  $47,390       $71,110
                                                                                    =======       =======
<FN> 
- ---------------
(1) Excludes 352,875 shares of Common Stock issuable upon the exercise of options outstanding at 
    December 31, 1995, of which options to purchase 230,465 shares were then exercisable. See Note I of 
    notes to the Company's financial statements appearing elsewhere in this Prospectus for a description 
    of the Company's stock option plans.
</TABLE>

 
                                      14

<PAGE>   17

<TABLE>
 
                           SELECTED FINANCIAL DATA
 
        The following table contains certain selected financial data of the
Company and is qualified by the more detailed financial statements and notes
thereto included elsewhere in this Prospectus. The selected financial data
presented below as of September 30, 1994 and 1995, and for each of the three
years in the period ended September 30, 1995, have been derived from the
Company's financial statements, which have been audited by Coopers & Lybrand
L.L.P., independent accountants, and are included elsewhere and incorporated by
reference in this Prospectus. The selected financial data presented below as of
September 30, 1993, 1992 and 1991, and for each of the two years in the period
ended September 30, 1992, are derived from the Company's audited financial
statements, which financial statements are not included or incorporated by
reference in this Prospectus. The selected financial data presented below for
the three months ended December 31, 1994 and 1995 have been derived from
unaudited financial statements of the Company and, in the opinion of
management, include all adjustments (consisting only of normal recurring
adjustments) necessary to present fairly the quarterly selected financial
information. The results for the three months ended December 31, 1995 are not
necessarily indicative of the results of operations for the entire fiscal year
or any other period. The information set forth below should be read in
conjunction with the Company's financial statements and notes thereto appearing
elsewhere or incorporated by reference in this Prospectus.
 
<CAPTION>
                                                                                                THREE MONTHS
                                                                                                    ENDED
                                                     YEAR ENDED SEPTEMBER 30,                   DECEMBER 31,
                                        --------------------------------------------------    -----------------
                                         1991       1992       1993       1994      1995       1994      1995
                                        -------    -------    -------    ------    -------    ------    -------
                                             (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
<S>                                     <C>        <C>        <C>        <C>       <C>        <C>       <C>
STATEMENT OF OPERATIONS DATA:
  Revenues:
    License fees......................  $ 4,000    $ 1,550    $ 1,010    $5,505    $ 5,000    $   --    $    --
    Royalties.........................    1,005      1,314        906        16        189        --         75
    Product sales.....................    3,836      4,062      3,836       281      2,120        55         --
    Contract research and
      development.....................    2,051        811        403        --         --        --         --
    Interest, dividends and net gains
      and losses on sales of
      securities......................    1,296      2,513      2,823     1,845      2,287       682        452
                                        -------    -------    -------    ------    -------    ------    -------
         Total revenues(1)............   12,188     10,250      8,978     7,647      9,596       737        527
  Costs and expenses:
    Cost of product sales.............    1,705      1,737      1,526        55        425        11         --
    Contract research and development
      expenses........................      708        607        193        --         --        --         --
    Company-sponsored research and
      development expenses............    4,935      5,432      6,863     6,622      8,602     1,598      2,161
    Charge (credit) for purchase of
      in-process research and
      development(2)..................    6,250         --         --       760       (380)     (380)        --
    Selling, general and
      administrative expenses.........    2,593      2,202      2,778     1,964      1,759       316        291
                                        -------    -------    -------    ------    -------    ------    -------
    Total costs and expenses..........   16,191      9,978     11,360     9,401     10,406     1,545      2,452
  Other income:
    Gain on sale of in vitro product
      line(1).........................       --         --         --     2,650      3,405        --         --
                                        -------    -------    -------    ------    -------    ------    -------
    Income (loss) before provision for
      income taxes and cumulative
      effect of accounting change.....   (4,003)       272     (2,382)      896      2,595      (808)    (1,925)
    Income tax provision..............     (413)        --         --         8        400        --         --
                                        -------    -------    -------    ------    -------    ------    -------
    Income (loss) before cumulative
      effect of accounting change.....   (3,590)       272     (2,382)      888      2,195      (808)    (1,925)
    Cumulative effect of accounting
      change(3).......................       --         --         --        --        118       118         --
                                        -------    -------    -------    ------    -------    ------    -------
    Net income (loss).................  $(3,590)   $   272    $(2,382)   $  888    $ 2,313    $ (690)   $(1,925)
                                        =======    =======    =======    ======    =======    ======    =======
    Net income (loss) per share.......  $ (0.70)   $  0.04    $ (0.36)   $ 0.13    $  0.34    $(0.10)   $ (0.28)
                                        =======    =======    =======    ======    =======    ======    =======
    Weighted average number of common
      and common equivalent shares....    5,141      6,760      6,651     6,807      6,871     6,718      6,756
</TABLE>

 
                                      15

<PAGE>   18
 

<TABLE>
<CAPTION>
                                                         SEPTEMBER 30,                          DECEMBER 31,
                                      ---------------------------------------------------    ------------------
                                       1991       1992       1993       1994       1995       1994       1995
                                      -------    -------    -------    -------    -------    -------    -------
<S>                                   <C>        <C>        <C>        <C>        <C>        <C>        <C>
BALANCE SHEET DATA:
  Cash and cash equivalents.........  $17,278    $30,804    $25,838    $ 6,462    $ 1,066    $ 4,385    $ 2,526
  Marketable securities.............      691      8,675     10,905     33,199     36,561     33,266     37,691
  Working capital...................   19,242     40,912     37,547     38,891     41,985     37,615     40,386
  Total assets......................   25,763     48,128     45,878     46,673     50,843     45,428     48,715
  Total stockholders' equity........   24,460     47,086     44,654     45,451     49,071     44,438     47,390
<FN> 
- ---------------
(1) On October 15, 1993, the Company sold its in vitro product line to PerSeptive Biosystems, Inc. and recorded 
    a $2,650,000 gain on the sale. The sale also included a contingent earn-out based on 1995 revenues which
    resulted in a $3,405,000 gain in 1995. Exclusive of the in vitro product line revenues, 1993 total revenues 
    would have been $3,961,000 consisting of license fees of $1,000,000, contract research and development of 
    $138,000 and interest, dividends and net gains and losses on sales of securities of $2,823,000.
 
(2) In August 1994, the Company reacquired the development and marketing rights to the MRI contrast agent 
    Combidex previously licensed to Squibb Diagnostics, a division of Bristol-Myers Squibb Co., and recorded a 
    related $760,000 charge for the purchase of in-process research and development. In the first fiscal quarter 
    of 1995, a credit for $380,000 was recorded to the purchase of in-process research and development as a 
    result of an amendment of the agreement between the Company and Squibb. See "Management's Discussion and 
    Analysis of Financial Condition and Results of Operations" and the Company's financial statements and notes 
    thereto appearing elsewhere in this Prospectus.
 
(3) In the first quarter of fiscal 1995, the Company adopted Statement of Financial Accounting Standards No. 115, 
    "Accounting for Certain Investments in Debt and Equity Securities," which requires that marketable securities
    classified as available for sale be recorded at fair market value, and recorded a cumulative change of $118,000.
</TABLE>

 
                                      16

<PAGE>   19
 

         MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
                          AND RESULTS OF OPERATIONS
 
OVERVIEW
 
        Since its inception in November 1981, the Company has focused its
efforts on developing its core superparamagnetic iron oxide particle
technology. In recent years, the Company's efforts have been focused primarily
on the development of MRI contrast agents and, to a lesser extent, on the
development of a drug delivery platform that targets therapeutics to the liver.
The Company has funded its operations with cash from license fees, royalties,
sales of its products, the proceeds of financings, income earned on invested
cash and fees from contract research performed for third parties. The Company's
long-term viability and growth will depend on the successful commercialization
of products resulting from its research activities. Among other things,
successful commercialization of the Company's products will require obtaining
necessary governmental approvals in a timely manner, attracting and retaining
key employees and responding to technological changes in the marketplace.
 
        The Company's operating results may continue to vary significantly from
quarter to quarter or from year to year depending on a number of factors,
including: (i) the timing of payments from corporate partners; (ii) the
introduction of new products; (iii) the timing and size of orders from
customers; and (iv) the general level of acceptance of the Company's products.
Profits may vary significantly from quarter to quarter or year to year based on
the timing of revenue and expense. Revenue or profits in any period will not
necessarily be indicative of results in subsequent periods and there can be no
assurance that the Company will achieve consistent profitability or that
revenue growth will occur in the future.
 
        A substantial portion of the Company's expenses consists of research
and development expenses. The Company expects its research and development
expenses to increase as it funds additional clinical trials and associated
toxicology and pharmacology studies and devotes resources to developing
additional contrast agents and hepatic drug product candidates.
 
        On October 15, 1993, the Company sold its in vitro product line to
PerSeptive Biosystems, Inc. ("PerSeptive") for $4,156,674 in PerSeptive common
stock plus an earn-out (the "Earn-Out") based on PerSeptive's 1995 in vitro
product line revenues. The Company recognized a pretax gain of $2,649,580 for
the fiscal year ended September 30, 1994. In the fourth fiscal quarter of 1995,
the Earn-Out value was determined to be $3,404,527. As a result, the Company
recorded a pretax gain of $3,404,527 and recorded an account receivable for
such amount in the fourth fiscal quarter of 1995. In the first fiscal quarter
of 1996, the Company received 378,080 additional shares of PerSeptive common
stock as payment of the Earn-Out, which shares were included as part of the
Company's marketable securities at December 31, 1995.
 
        In August 1994, the Company signed an agreement with Bristol-Myers
Squibb Co. ("Bristol-Myers") to reacquire the development and marketing rights
to Combidex, which had been held by Squibb Diagnostics, a division of
Bristol-Myers (the "Combidex Transaction"). As part of this transaction, the
Company agreed to pay Bristol-Myers $1,000,000 in cash, of which $500,000 was
paid upon execution of the agreement (the "Bristol-Myers Agreement") and
$500,000 was to be paid upon acceptance by the Company of 1,200 vials of
Combidex from Bristol-Myers acceptable for use in worldwide preclinical and
clinical studies. In addition, Bristol-Myers returned to the Company a warrant,
which was valued at $240,000, to purchase 600,000 shares of Common Stock (the
"Bristol-Myers Warrant"). The Company also agreed to pay up to $2,750,000 to
Bristol-Myers for royalties on future sales by the Company of Combidex. As a
result of the Combidex Transaction, the Company recorded a $760,000 charge in
the fiscal year ended September 30, 1994 for the purchase of in-process
research and development.
 
        In the first fiscal quarter ended December 31, 1994, the Company and
Bristol-Myers amended the Bristol-Myers Agreement. As a result of this
amendment, the Company was relieved of its obligation to pay $500,000 to
Bristol-Myers, and Bristol-Myers was relieved of its obligation to deliver
Combidex to the Company for clinical trials. Accordingly, in the first fiscal
quarter ended December 31, 1994, the Company recorded a credit for $380,000 to
the purchase of in-process research and development and adjusted the value of
the warrant downward by $120,000.
 
                                      17

<PAGE>   20
 
        In the fiscal quarter ended December 31, 1994, the Company adopted
Statement of Financial Accounting Standards No. 115, "Accounting for Certain
Investment in Debt and Equity Securities" ("SFAS 115"), which requires that
marketable securities classified as available for sale be recorded at fair
market value. The adoption of SFAS 115 resulted in a cumulative effect of
accounting change of $117,540 in the first fiscal quarter ended December 31,
1994.
 
  THREE MONTHS ENDED DECEMBER 31, 1995 AND 1994
 
        Total revenues for the fiscal quarter ended December 31, 1995 decreased
29% to $526,859 from $737,245 for the fiscal quarter ended December 31, 1994.
The decrease in revenues compared to the fiscal quarter ended December 31, 1994
resulted primarily from the absence of product sales and a reduction in
interest and dividend income earned on investments. This decrease was partially
offset by an increase in revenue from royalties.
 
        Royalties for the fiscal quarter ended December 31, 1995 were $75,000
and were paid by Guerbet on European product sales of Feridex I.V. and
GastroMARK. There were no royalties for the fiscal quarter ended December 31,
1994. There were no product sales during the fiscal quarter ended December 31,
1995 compared to $55,259 of product sales in the comparable prior fiscal year
period.
 
        Interest, dividends and gains and losses on sales of securities
resulted in revenues of $451,859 for the fiscal quarter ended December 31, 1995
compared to $681,986 for the fiscal quarter ended December 31, 1994. Interest
income for the fiscal quarter ended December 31, 1995 was $80,163 less than the
fiscal quarter ended December 31, 1994 primarily due to a reduction of funds
invested in money market accounts. Dividend income for the fiscal quarter ended
December 31, 1995 was $135,263 less than the fiscal quarter ended December 31,
1994 primarily due to a reduction of funds invested in dividend paying
preferred stocks.
 
        Research and development expenses for the fiscal quarter ended December
31, 1995 increased 35% to $2,160,560 from $1,597,847 for the fiscal quarter
ended December 31, 1994. The increase is primarily a result of costs associated
with Phase II and Phase III human clinical trials for Combidex. The fiscal
quarter ended December 31, 1994 reflected a $380,000 credit as a result of the
amendment of the Bristol-Myers Agreement that was entered into in connection
with the Combidex Transaction. Selling, general and administrative expenses
decreased 8% to $290,984 for the first fiscal quarter ended December 31, 1995
from $315,890 for the first fiscal quarter ended December 31, 1994. The
decrease was primarily due to a decrease in litigation-related legal and
consulting fees.
 
        The Company incurred no costs of product sold for the fiscal quarter
ended December 31, 1995 compared to $11,050 for the first fiscal quarter ended
December 31, 1994.
 
        For the reasons stated above, there was a net loss of $1,924,685, or
$0.28 per share, for the fiscal quarter ended December 31, 1995 compared to a
net loss of $807,542 or $0.12 per share, for the fiscal quarter ended December
31, 1994 before the cumulative effect of the accounting change resulting from
the adoption of SFAS 115. Including the cumulative effect of the accounting
change of $117,540, net loss and net loss per share for the fiscal quarter
ended December 31, 1994 were $690,002 and $0.10 per share, respectively.
 
  YEARS ENDED SEPTEMBER 30, 1995 AND 1994
 
        Total revenues for the fiscal year ended September 30, 1995 increased
26% to $9,597,261 from $7,646,904 for the fiscal year ended September 30, 1994.
 
        License fee revenues for the fiscal year ended September 30, 1995 were
$5,000,000 compared to $5,505,000 for fiscal year ended September 30, 1994. The
Company received a nonrefundable $5,000,000 license fee on February 1, 1995
from Berlex under an agreement granting Berlex a product license and exclusive
marketing rights to Feridex I.V. in the United States. License fee revenues for
the fiscal year ended September 30, 1994 included a nonrefundable license fee
of $3,000,000 paid by Squibb Diagnostics, a division of Bristol-Myers, for the
right to market Combidex (which was paid prior to the Combidex Transaction) and
a nonrefundable milestone license fee of $2,500,000 paid by Sterling Winthrop,
Inc., a subsidiary of Eastman Kodak Company ("Sterling"), for the Company's
filing of an NDA for Feridex I.V. On October 6, 1994, the
 
                                      18

<PAGE>   21
 
Company terminated its marketing and distribution agreement with Sterling for
Feridex I.V. as a direct result of the sale by Sterling of its prescription
pharmaceuticals business. The agreement with Sterling was not assignable without
the Company's consent, which was not granted.
 
        Product sales for the fiscal year ended September 30, 1995 were
$2,120,457 compared to $280,975 for the fiscal year ended September 30, 1994.
Product sales increased as a result of $2,013,869 of Feridex I.V. sales to
Guerbet. Product sales of $280,975 for the fiscal year ended September 30, 1994
were primarily attributable to the sale of GastroMARK to Guerbet.
 
        Royalties for the fiscal year ended September 30, 1995 were $189,493
compared to $15,924 for the fiscal year ended September 30, 1994. The royalties
were earned on sales to Guerbet of Feridex I.V. and GastroMARK.
 
        Interest, dividends and gains and losses on sales of securities
resulted in revenues of $2,287,311 in the fiscal year ended September 30, 1995
compared to revenues of $1,845,005 in the fiscal year ended September 30, 1994.
These amounts include interest and dividends of $2,232,345 for the fiscal year
ended September 30, 1995 compared to $1,801,436 for the fiscal year ended
September 30, 1994. The increase was primarily a result of an increase in
interest revenue from United States treasury notes. Net gains from the sale of
marketable securities were $54,966 for the fiscal year ended September 30, 1995
compared to a net gain of $161,109 in the fiscal year ended September 30, 1994.
There were net unrealized losses of $117,540 resulting from an adjustment to
the carrying value of marketable securities from cost to market during fiscal
1994, which were reversed in connection with the adoption of SFAS 115 in the
fiscal quarter ended December 31, 1994. As a result of the adoption of SFAS
115, the Company recorded a cumulative effect of the accounting change of
$117,540.
 
        The cost of product sales for the fiscal year ended September 30, 1995
was $425,187 compared to $54,983 for the fiscal year ended September 30, 1994.
The cost of product sales was 20% of sales for both fiscal years. Research and
development expenses for the fiscal year ended September 30, 1995 increased 30%
to $8,601,791 from $6,621,929 for the fiscal year ended September 30, 1994. The
increase in research and development expenses was primarily due to expenditures
for the clinical trials of Combidex and pre-clinical development of the
Company's targeted drug delivery program. In the fiscal year ended September
30, 1995, the Company recorded a $380,000 credit as a result of the amendment
to the Bristol-Myers Agreement that was entered into in connection with the
Combidex Transaction. Selling, general and administrative expenses for the
fiscal year ended September 30, 1995 were $1,759,348, a decrease of 10% from
$1,963,480 for the fiscal year ended September 30, 1994. The decrease was
primarily due to a decrease in litigation-related legal and consulting fees.
 
        On October 15, 1993, the Company sold its in vitro product line to
PerSeptive and recognized a pretax gain of $2,649,580 for the fiscal year ended
September 30, 1994. In the fourth fiscal quarter of 1995, the Company
recognized a pretax gain of $3,404,527 from the Earn-Out, which was based on
PerSeptive's 1995 in vitro product line revenues.
 
        In the fiscal year ended September 30, 1995, the Company recorded a net
profit of $2,195,462, or $0.32 per share, before the cumulative effect of an
accounting change resulting from the adoption of SFAS 115. Including the
cumulative effect of an accounting change of $117,540, or $0.02 per share, net
income was $2,313,002, or $0.34 per share, for the fiscal year ended September
30, 1995 compared to net income of $888,092, or $0.13 per share, for the fiscal
year ended September 30, 1994.
 
  YEARS ENDED SEPTEMBER 30, 1994 AND 1993
 
        Total revenues of the Company decreased 15% to $7,646,904 in the fiscal
year ended September 30, 1994 compared to $8,978,451 in the fiscal year ended
September 30, 1993. Fiscal year 1993 included $5,017,000 of revenues from the
Company's in vitro product line that was sold to PerSeptive on October 15,
1993.
 
        License fee revenues for the fiscal year ended September 30, 1994 were
$5,505,000 compared to $1,010,000 for the fiscal year ended September 30, 1993.
License fee revenue for fiscal 1994 included a nonrefundable license fee of
$2,500,000 paid by Sterling. The fee was a milestone payment for the Company's
 
                                      19

<PAGE>   22
 
filing of an NDA with the FDA for Feridex I.V. Also included in fiscal 1994
license fee revenue was a nonrefundable license fee of $3,000,000 paid by Squibb
Diagnostics, a division of Bristol-Myers, for the right to market Combidex. In
August 1994, the Company reacquired from Bristol-Myers the development and
marketing rights to Combidex in the Combidex Transaction. License fee revenue
for fiscal 1993 included a nonrefundable $1,000,000 license fee paid by Sterling
in September 1993 upon the signing of a license agreement for a product license
and exclusive marketing rights to Feridex I.V. in the United States, Canada,
Mexico and Australia.
 
        Royalties for the fiscal year ended September 30, 1994 were $15,924
compared to $906,138 for the fiscal year ended September 30, 1993. The royalty
revenues for fiscal 1993 were attributable to the in vitro license agreements
which were included as a part of the October 1993 sale of the in vitro product
line.
 
        Product sales of $280,975 for the fiscal year ended September 30, 1994
were primarily attributable to the European launch of GastroMARK. Product sales
for the fiscal year ended September 30, 1993 were $3,836,300 for the in vitro
products which were included as part of the sale to PerSeptive.
 
        There were no fees from contract research and development for the
fiscal year ended September 30, 1994 compared to $402,911 for the fiscal year
ended September 30, 1993. Included in the contract research and development
revenues for the fiscal year ended September 30, 1993 was $205,581 of fees for
several research projects with one party for the development of specific in
vitro products that were completed in fiscal 1993.
 
        Interest, dividends and gains and losses on sales of securities
resulted in revenues of $1,845,005 in the fiscal year ended September 30, 1994
compared to revenues of $2,823,102 in the fiscal year ended September 30, 1993.
These amounts include interest and dividends of $1,801,436 for the fiscal year
ended September 30, 1994 compared to $1,791,676 for the fiscal year ended
September 30, 1993. Net gain from sales of marketable securities was $161,109
in the fiscal year ended September 30, 1994 compared to a net gain of
$1,031,426 for the fiscal year ended September 30, 1993. There were net
unrealized losses of $117,540 resulting from an adjustment to the carrying
value of marketable securities from cost to market during fiscal 1994. No
similar adjustment was required at the end of fiscal 1993.
 
        The cost of product sales for the fiscal year ended September 30, 1994
was related to the sale of contrast agents. Due to the sale of the in vitro
product line to PerSeptive, there were no in vitro production costs for the
fiscal year ended September 30, 1994. There were no contract research and
development expenses in the fiscal year ended September 30, 1994 due to the
absence of such contracts. For the fiscal year ended September 30, 1993,
contract research and development expenses were $193,391. Company-sponsored
research and development expenses for the fiscal year ended September 30, 1994
were $6,621,929, a decrease of 4% compared to $6,863,229 for the fiscal year
ended September 30, 1993. The decrease in research and development expenses for
the fiscal year ended September 30, 1994 was primarily due to the absence of
research and development activity for the in vitro product line offset by
increases in the in vivo research and development expenses. In the fiscal year
ended September 30, 1994, the Company recorded a $760,000 charge for the
purchase of in-process research and development as a result of the Combidex
Transaction. Selling, general and administrative expenses decreased from
$2,777,840 in the fiscal year ended September 30, 1993 to $1,963,480 in the
fiscal year ended September 30, 1994. The decrease was primarily due to the
absence of selling, general and administrative expenses associated with the in
vitro product line which was sold to PerSeptive.
 
        On October 15, 1993, the Company sold its in vitro product line to
PerSeptive and recognized a pretax gain of $2,649,580 for the fiscal year ended
September 30, 1994. Revenue and pretax income from the in vitro product line
for the fiscal year ended September 30, 1994 reflected 15 days of revenue and
income which were immaterial.
 
        In the fiscal year ended September 30, 1994, the Company recorded a net
profit of $888,092, or $0.13 per share, compared to a net loss of $2,381,573,
or $0.36 per share, in the fiscal year ended September 30, 1993.
 
LIQUIDITY AND CAPITAL RESOURCES
 
        At December 31, 1995, the Company's cash and cash equivalents totaled
$2,525,965, representing an increase of $1,459,546 from cash and cash
equivalents at September 30, 1995. In addition, the Company had
 
                                      20

<PAGE>   23
 
marketable securities of $37,690,764 at December 31, 1995 as compared to
marketable securities of $36,561,263 at September 30, 1995. Included in the
Company's marketable securities at December 31, 1995 are the 378,080 shares of
PerSeptive common stock received in such quarter from the Earn-Out due to the
Company as a result of the sale of the in vitro product line to PerSeptive.
 
        Net cash used in operating activities was $429,932 in the first fiscal
quarter ended December 31, 1995 compared to net cash used in operating
activities of $1,200,231 in the first fiscal quarter ended December 31, 1994.
Cash used in operating activities for the first fiscal quarter ended December
31, 1995 was less than the cash used in operating activities for the first
fiscal quarter ended December 31, 1994 due primarily to a reduction in accounts
receivable of $1,150,328, offset by an increase in the net loss for the
quarter.
 
        Cash provided by investing activities was $1,818,801 for the first
fiscal quarter ended December 31, 1995 compared to $947,303 used in investing
activities in the first fiscal quarter ended December 31, 1994. Cash provided
by investing activities in the first fiscal quarter ended December 31, 1995
included the proceeds of $2,450,534 from the sale of marketable securities and
proceeds from a $1,000,000 matured United States treasury note. Offsetting
these proceeds was the purchase of marketable securities of $1,450,162 in the
first fiscal quarter ended December 31, 1995. Cash provided by financing
activities for the first fiscal quarter ended December 31, 1995 and 1994 was
$70,677 and $70,054 respectively, which resulted from the issuance of common
stock.
 
        Capital expenditures in the first fiscal quarter ended December 31,
1995 were $181,571 compared to $495,300 in the first fiscal quarter ended
December 31, 1994. Capital expenditures in the first fiscal quarter ended
December 31, 1994 included an upgrade to the Company's magnetic resonance
imaging equipment and furnishings and equipment associated with the
establishment of the Clinical Development Group in the Company's Princeton, New
Jersey office. The Company has no current commitment for any significant
expenditures on property, plant and equipment. The Company expects that
expenditures for research and development for the remainder of fiscal 1996 will
continue to increase due to human clinical trials for the Company's development
stage contrast agents and antiviral hepatitis therapeutics.
 
        The Company anticipates that the net proceeds of the Offering and
interest earned thereon, together with existing funds, will be sufficient to
satisfy its operating expenses and capital requirements through at least the
end of 1997. The Company will likely need significant additional funding in
order to continue its research and product development programs and the
preclinical testing and clinical trials of its targeted therapeutic product
candidates.
 
                                      21

<PAGE>   24
 
 
                                   BUSINESS
 
COMPANY OVERVIEW
 
     Advanced Magnetics develops, manufactures and markets organ-specific
contrast agents to improve the diagnostic capabilities of soft tissue MRI scans
and is developing a drug delivery platform that targets therapeutics to the
liver for the treatment of certain liver diseases. The Company is a leader in
the development of organ-specific superparamagnetic MRI contrast agents,
including Feridex I.V. for the liver, GastroMARK for the gastrointestinal
system, and Combidex for the liver, spleen, lymphatic system and blood flow.
Sales of Feridex I.V. have commenced in Europe, and the Company recently
received an approvable letter from the FDA for this product. GastroMARK has been
approved for marketing in several European countries and Canada, and an NDA for
this product was submitted to the FDA in November 1993. With respect to
Combidex, the Company and Guerbet have completed Phase II clinical trials in
both the United States and Europe for several indications. The Company has
completed patient enrollment for Phase III trials for Combidex in the United
States for imaging liver lesions and expects to begin separate phase iii trials
in 1996 for Combidex as a blood flow contrast agent in MRA. In 1996, the Company
and Guerbet expect to begin Phase III trials for Combidex in the United States
and Europe for imaging of lymph nodes. In addition to these contrast agents,
Advanced Magnetics is applying its organ-specific technology and expertise to
the development of a drug delivery platform targeting therapeutics to the liver
and expects to commence clinical trials in Europe for a treatment of hepatitis B
in 1996.
 
     MRI is a diagnostic imaging technique that is used to identify internal
abnormalities and changes in structure. Contrast agents increase the usefulness
of MRI by allowing radiologists to differentiate structures and organs with
greater diagnostic confidence. The Company believes that MRI studies produced
with contrast agents are clearer and permit the identification of smaller
abnormalities than images produced by MRI without contrast agents or CECT. MRI
contrast agents frequently allow for more accurate diagnosis and monitoring of
treatment results and may be a cost-effective way to optimize medical treatments
and to improve patient outcomes. Currently, the primary use of MRI is for
studies of the central nervous system, which accounted for approximately 74% of
the estimated 7.4 million MRI studies performed in the United States in 1994.
Approximately 29% of these MRI studies were contrast enhanced at a cost to
payors of approximately $145 million for contrast agents. The Company believes
that the development of effective contrast agents will increase the use of MRI
as a diagnostic imaging technique and will allow MRI to be used for a wider
range of applications, in turn generating additional demand for MRI contrast
agents.
 
     No MRI contrast agents designed specifically for the liver or the lymphatic
system are currently being marketed anywhere in the world, except for the
Company's Feridex I.V. liver agent, which is being sold in Europe. The liver and
the lymphatic system are among the principal sites for metastasis of many common
cancers (including colon, prostate and breast cancer). CECT is currently the
primary imaging technique used to confirm a preliminary or suspected diagnosis
of liver cancer, and the Company believes that approximately 1.75 million CECT
liver scans were performed in the United States in 1995 at an estimated contrast
agent cost of over $100 million. With respect to the lymphatic system, there
currently are no effective imaging techniques. An MRI contrast agent that
localizes to and causes contrast enhancement of the lymph nodes, such as
Combidex, could allow for more accurate disease diagnosis and monitoring of
treatment results. The Company believes that GastroMARK, because it enhances the
contrast between the bowel and other abdominal structures, will increase the use
of MRI as an imaging technology for the abdomen. In light of these potential
applications of MRI contrast agents, the Company believes that it is well
positioned to benefit from the expected demand for such agents and to capture a
portion of the over $3 billion worldwide market for imaging agents,
approximately $294 million of which was associated with MRI in 1995.
 
     In order to facilitate the marketing and distribution of its contrast
agents, the Company has entered into strategic relationships with certain
established pharmaceutical companies. These relationships, both in the United
States and abroad, include: (i) Guerbet, a leading European producer of contrast
agents, in Western Europe and Brazil; (ii) Eiken, one of Japan's leading medical
diagnostics manufacturers, in Japan; (iii) Berlex, the leading marketer in the
United States of MRI contrast agents, in the United States; and
 
                                       22

<PAGE>   25
 
(iv) Mallinckrodt, a leading manufacturer in the United States of contrast
agents, in the United States, Canada and Mexico.
 
     The Company's expertise in organ-specific technology provides it with
biopharmaceutical opportunities beyond its core MRI contrast agent products.
Advanced Magnetics is developing a drug delivery platform that targets
therapeutics to the liver. The Company believes that arabinogalactan, a
naturally occurring polysaccharide that binds to the ASG receptor found in
abundance on hepatocytes, the principal cells comprising the liver, has
commercial promise in drug delivery. Arabinogalactan was initially developed by
the Company as a delivery agent for targeting contrast agents to the liver
because of its high specificity, low cost and lack of toxicity. The Company is
currently focusing on the development of a product for the treatment of
hepatitis B consisting of a conjugate of arabinogalactan and AraAMP. AraA is an
existing therapeutic agent that has shown efficacy in the treatment of hepatitis
B, but is unacceptably toxic when used in an unconjugated form. Phase I clinical
trials for this product candidate are expected to begin in 1996 in Europe.
Advanced Magnetics intends to study the efficacy of other therapeutic agents
combined with arabinogalactan for the treatment of hepatitis C, hepatitis D and
liver cancer.
 
MRI CONTRAST AGENTS
 
  OVERVIEW
 
     Diagnostic Imaging.  Diagnostic imaging is generally a non-invasive method
to visualize internal structures, abnormalities or anatomical changes in order
to diagnose disease and injury. Today, the most widely accepted imaging
techniques include x-ray (including x-ray angiography), ultrasound, nuclear
medicine, CT and MRI. Since the introduction of x-ray, the need for increasingly
accurate and detailed non-invasive visualization of soft tissue has increased.
For example, diagnostic imaging frequently is used to determine whether a cancer
has metastasized to other organs and to assist physicians in determining whether
a treated cancer has recurred or the location of additional tumors. In addition,
diagnostic imaging is used in the diagnosis of disease and injury conditions
affecting the cardiovascular and central nervous systems and certain joints,
such as the knee and shoulder. In 1994, over 76 million soft tissue and organ
imaging procedures were performed in the United States. The choice of diagnostic
imaging technique to be used in any particular circumstance depends upon a
variety of factors, including the particular disease or condition to be studied,
image quality, availability of imaging machines, availability of contrast agents
and cost. There is no imaging technique that is considered superior to all
others for most or all applications.
 
     Contrast agents play a significant role in improving the quality of
diagnostic images by increasing contrast between different internal structures
or types of tissues. The availability of an effective contrast agent often
determines the choice of imaging technique for a particular procedure.
Consequently, contrast agents, which are administered intravenously or orally,
are widely used when available. In 1994, approximately 31 million diagnostic
imaging procedures using contrast agents were performed in the United States.
The cost to payors of the contrast agents used in these procedures was
approximately $1.3 billion. Currently available imaging techniques can be of
limited usefulness in visualizing certain soft-tissue structures. For example,
clinically useful diagnostic imaging of small lesions in lymph nodes, a common
site of metastasis for some frequently occurring cancers such as breast cancer,
is not currently available because, the Company believes, there are no effective
contrast agents for imaging lymph nodes.
 
     Magnetic Resonance Imaging.  Introduced in the 1980's, MRI is the
diagnostic imaging technique of choice for the central nervous system and is
widely used for the imaging of ligaments and tendons. MRI, which represents the
first major advance in imaging since the advent of CT scanning, provides
high-quality spatial resolution and does not use radiation. In MRI procedures,
the patient is placed within the core of a large magnet where radio frequency
signals are transmitted into the patient's body. The interaction of the radio
frequency signal with the patient's body produces signals that are processed by
a computer to create cross-sectional images.
 
     MRI contrast agents currently marketed in the United States are used
primarily in imaging the central nervous system. In 1994, there were
approximately 7.4 million MRI scans performed in the United States, of which
approximately 2.2 million were performed with a contrast agent. The worldwide
market for MRI
 
                                       23

<PAGE>   26
 
contrast agents in 1994 was approximately $250 million, and the United States
market was approximately $145 million.
 
     MRI Contrast Agent Market Opportunity.  The Company believes that there is
a significant market opportunity for its organ-specific contrast agents for the
following reasons:
 
     - The Company believes that its contrast agents for imaging the liver,
       spleen, lymphatic system, blood flow and gastrointestinal system will
       have a strong competitive position because the Company believes that they
       either (i) permit more diagnostically useful images than images produced
       by CECT, the current diagnostic imaging technique of choice, or (ii) meet
       a perceived need for visualization of structures which existing imaging
       techniques do not adequately image, such as tumors in lymph nodes.
 
     - Existing MRI equipment is often not fully utilized. The Company believes
       that its contrast agents will encourage greater utilization of equipment
       with relatively little increase in marginal cost to imaging centers and
       the health care system.
 
     - MRI with the Company's contrast agents may detect smaller tumors than
       CECT, potentially resulting in earlier or more confident disease
       diagnoses.
 
     - The Company believes that the use of its contrast agents may result in an
       overall reduction in costs to the health care system, even though
       contrast enhanced MRI studies cost more than CECT studies, because MRI
       with the Company's contrast agents is likely to reduce incorrect
       diagnoses, increase diagnostic confidence and reduce unnecessary surgery.
 
     - In keeping with both good medical practice and the health care system
       pressure to lower costs, health care providers and payors often prefer
       the use of non-invasive means of diagnosis. Consequently, the Company
       believes that Combidex, its intravenous contrast agent under development
       for use in MRA, could be widely adopted to replace x-ray angiography,
       which uses catheters threaded through veins.
 
     The Company has developed two MRI contrast agents, Feridex I.V. for imaging
of the liver and GastroMARK for imaging of the gastrointestinal tract, and is
also developing a third product, Combidex, for imaging of the liver, spleen and
lymphatic system and blood flow in MRA. No MRI contrast agents designed
specifically for imaging the liver or blood flow in MRA are currently being
marketed anywhere in the world, except for the Company's Feridex I.V. liver
agent in Europe. No contrast agents for any imaging technique are marketed
anywhere in the world for the spleen or the lymphatic system.
 
  TECHNOLOGY
 
     Advanced Magnetics' core imaging agent technology is based on the design
and manufacture of extremely small, polysaccharide-coated superparamagnetic iron
oxide particles of controlled sizes. The superparamagnetic particles range in
size from approximately one-thousandth to approximately one-twentieth the size
of a normal red blood cell. When placed in a magnetic field, superparamagnetic
iron oxide particles become strongly magnetic, but do not retain their magnetism
once the field is removed. The powerful magnetic properties of the Company's
iron oxide particles result in images that show greater contrast to increase the
information available to the reviewing radiologist. The Company's technology and
expertise enable it to synthesize, sterilize and stabilize superparamagnetic
particles in a manner necessary for their use in pharmaceutical products as MRI
contrast agents to aid in the diagnosis of cancer and other diseases.
 
     Feridex I.V., which is composed of dextran-coated superparamagnetic iron
oxide particles, is administered by intravenous injection. This MRI contrast
agent has a relatively short blood circulating half-life and is primarily taken
up by the Kupffer cells of the liver. The highly differentiated Kupffer cells,
which are evenly distributed and comprise about 5% of total cells in normal
liver tissue, remove foreign materials from the blood stream. Feridex I.V. is
not absorbed by tumors in the liver, thereby dramatically enhancing the contrast
between healthy and cancerous liver tissue.
 
     Combidex, which is composed of smaller dextran-coated superparamagnetic
iron oxide particles, has a relatively long blood circulating half-life. The
long circulating half-life of Combidex will permit it to be used in analyzing
various soft tissues and organs. When initially injected, Combidex is designed
to be used in
 
                                       24

<PAGE>   27
 
analyzing blood flow. The Company believes that Combidex will be used in MRA for
analyzing tissues such as the heart and brain and that it can be used to
delineate tissue damaged as a result of decreased blood flow caused by heart
attacks and strokes. The Company also believes that Combidex can be used to
identify tumors in the liver and spleen because tumors have different
vascularity than the surrounding tissues. Approximately 24 hours after
injection, an adequate amount of Combidex accumulates in normal lymph node
tissue to permit differentiation from tumor-infiltrated lymph nodes.
 
     GastroMARK, which is composed of silicone-coated superparamagnetic iron
oxide particles, is an oral MRI contrast agent designed to improve imaging of
abdominal organs by distinguishing between the loops of the bowel and other
abdominal organs and structures. When ingested, GastroMARK flows through and
darkens the bowel and causes it to appear darker on images than adjacent tissue.
By more clearly identifying the intestinal loops, GastroMARK improves
visualization of adjacent abdominal tissues, including the pancreas and pelvis.
 
     The Company's rights to its contrast agent technology are derived from and
protected by license agreements, patents, patent applications and trade secrets.
See "Patents and Trade Secrets."
 
TARGETED DRUG DELIVERY PLATFORM
 
  OVERVIEW
 
     The liver is the largest organ in the human body and is essential to many
critical functions, including processing of nutrients and producing many
necessary plasma proteins. Common diseases of the liver include hepatitis,
cancer and cirrhosis. Effective treatment of liver diseases is often limited by
the inability to deliver sufficient quantities of therapeutic pharmaceuticals to
the liver without creating unacceptable levels of toxicity in the rest of the
body. The Company believes the treatment of liver disease would be significantly
improved by delivering therapeutics to the liver while limiting the exposure of
the rest of the body to the drug. The Company discovered that arabinogalactan, a
compound it studied to target contrast agents to the liver, could be useful in
delivering therapeutic agents to hepatocytes, cells which comprise approximately
95% of the liver but do not exist in significant numbers in the rest of the
body. The Company's first therapeutic product under development is a conjugate
of arabinogalactan and AraAMP for the treatment of hepatitis B.
 
     Worldwide, chronic infection with hepatitis B is a major cause of morbidity
and mortality. Hepatitis B infects approximately 300 million persons worldwide.
During 1993, there were approximately 250,000 new infections in the United
States. Up to 1% of American adults are chronic carriers of hepatitis B.
However, in the Far East and in some tropical countries, prevalence rates for
hepatitis B range from 5% to 20%. Most people infected with hepatitis B develop
symptoms including malaise, anorexia, nausea, vomiting, dark urine, liver pain
and fever as well as signs of jaundice. Approximately 7% of people infected with
hepatitis B develop progressive liver damage that may result in portal fibrosis,
cirrhosis or liver cancer. Approximately 5% of people infected with hepatitis B
develop hepatitis D, a more virulent form of the disease that often results in
serious secondary liver damage and disease.
 
  TECHNOLOGY
 
     The Company's drug delivery platform technology includes joining a
therapeutic agent to a targeting agent, which binds specifically with certain
receptors on the surface of cells. Receptors are specialized protein structures
that will only bind with specific molecules. Certain receptors are prevalent
only or primarily on specific kinds of cells. For example, the ASG receptor
exists primarily in hepatocytes. After binding with the receptor, the targeting
agent and an attached pharmaceutical are transported into the cell, where the
pharmaceutical causes a therapeutic effect. The Company believes that target
drug delivery based on the binding action of targeting agents with receptors
offers the possibility of delivering effective therapeutic doses to affected
cells without general distribution of toxic agents throughout the body.
 
     In its first targeted drug delivery project, the Company has completed
preclinical testing of a potential therapeutic product for hepatitis B composed
of AraAMP and arabinogalactan. AraA, an antiviral agent which is used in the
United States and abroad for the treatment of herpes simplex, has not been
approved for
 
                                       25

<PAGE>   28
 
the treatment of hepatitis B in the United States because, although it is an
effective agent against the hepatitis virus, when administered systemically in
an unconjugated form, is often toxic to the bone marrow, blood cells and
peripheral nervous system at the dosage necessary to treat the hepatitis B
virus. AraA and other nucleoside products must be phosphorylated with three
phosphate ions in order to have a therapeutic effect. When AraA is injected
directly, however, most molecules of AraA do not become phosphorylated. The
Company believes that much of the toxicity associated with AraA results from
toxic compounds created when the drug breaks down in the body. The Company has
discovered that AraA, when phosphorylated with one phosphate (monophosphate) and
chemically linked with arabinogalactan prior to injection, shows far greater
therapeutic effect in animals and reduced toxicity. Toxicity is reduced because
(i) less therapeutic compound is needed since AraAMP is directed by the
arabinogalactan to hepatocytes through the ASG receptor, (ii) the probability of
successful triphosphorylation is increased by the targeted delivery of the
monophosphate to the cell and (iii) the arabinogalactan-AraAMP conjugate does
not, the Company believes, metabolize into any toxic product during its short
blood half-life.
 
     The Company believes that the delivery and use enhancements seen when
AraAMP is attached to arabinogalactan may be obtained with other therapeutic
agents. The attachment of a variety of therapeutic agents to arabinogalactan,
such as ribavirin and acyclovir, is an active area of research for Advanced
Magnetics and may lead to a series of arabinogalactan-delivered pharmaceuticals
for the treatment of such liver diseases as hepatitis B, hepatitis C, hepatitis
D and liver cancer.
 
     The Company holds two United States patents and a notice of allowance for a
European patent covering the delivery of therapeutic agents with
arabinogalactan. A third patent covering the use of arabinogalactan with
radiotherapy has been issued in the United States. The Company has also
developed a proprietary purification scheme for purifying arabinogalactan that
enables it to manufacture a pharmaceutical grade of arabinogalactan suitable for
use in the Company's therapeutic products. See "Patents and Trade Secrets."
 
                                       26

<PAGE>   29
 
PRODUCTS UNDER DEVELOPMENT
 
     This section contains certain forward-looking statements relating to the
timing of clinical trials and regulatory approvals and the expected use of the
Company's products. These statements should be considered in connection with the
risks set forth in "Risk Factors -- Early Stage of Product Commercialization;
Uncertainty of Product Development," "-- Government Regulation; No Assurance of
Regulatory Approval" and "-- Uncertainties Relating to Clinical Trials;
Technological Uncertainty."
 

<TABLE>
     The following table summarizes potential applications, marketing partners
and current United States and foreign status for each of the Company's products.
 
- ------------------------------------------------------------------------------------------------
                         ADVANCED MAGNETICS PRODUCTS UNDER DEVELOPMENT
 
<CAPTION>
                                          MARKETING         UNITED STATES          FOREIGN
    PRODUCT          APPLICATIONS          PARTNERS             STATUS              STATUS
- ----------------  ------------------  ------------------  ------------------  ------------------
<S>               <C>                 <C>                 <C>                 <C>
CONTRAST AGENTS
Feridex I.V.      Diagnosis of liver  Berlex (United      Approvable letter   Approved and
                  lesions             States), Eiken      received in         marketed in most
                                      (Japan), Guerbet    February 1996.      EU countries.
                                      (Western Europe                         Japanese NDA filed
                                      and Brazil)                             in March 1994.

Combidex          Diagnosis of        Guerbet (Western    Phase III           Phase III clinical
                  lesions of the      Europe and          liver/spleen trial  trials for
                  liver, spleen and   Brazil), Eiken      patient enrollment  lymphatic imaging
                  lymphatic system,   (Japan)             completed in early  expected to
                  as well as blood                        1996. Phase III     commence in Europe
                  flow in MRA                             clinical trials     in 1996. Phase I
                                                          for blood flow and  testing expected
                                                          lymphatic imaging   to begin in Japan
                                                          expected to         in 1996.
                                                          commence in 1996.

GastroMARK        Marking of the      Guerbet (Western    NDA submitted in    Approved and
                  bowel in abdominal  Europe and          November 1993.      marketed in
                  imaging             Brazil),                                several European
                                      Mallinckrodt                            countries,
                                      (United States,                         including France.
                                      Canada and Mexico)                      Approved in
                                                                              Canada.

TARGETED DRUG DELIVERY PRODUCTS
AraAMP-           Therapeutic for     --                  Preclinical         Clinical trials
arabinogalactan   hepatitis B                             research            expected to begin
conjugate                                                 completed.          in 1996.

Ribavirin-        Therapeutic for     --                  Preclinical         --
arabinogalactan   hepatitis C                             research in
conjugate                                                 process.
- ------------------------------------------------------------------------------------------------
</TABLE>

 
  CONTRAST AGENTS
 
     FERIDEX I.V.  The liver is a principal site for metastasis of primary
cancer originating in other parts of the body, particularly cancer of the colon,
a common cancer in the United States. Diagnosis of metastasis at an early stage
can be difficult because small tumors are frequently not accompanied by
detectable physical symptoms. Identification of metastatic tumors in the liver
has a significant impact on physicians' treatment plans for cancer. The Company
believes that Feridex I.V. will allow for MRI scans of liver tumors that may not
be visible with CT scanning, the most widely used technique for liver imaging.
The Company also believes that if an effective MRI contrast agent were available
for imaging the liver, a substantial number of liver scans now done using CT
scanning and other imaging techniques would instead, or also, use MRI.
 
                                       27

<PAGE>   30
 
     The Company received an approvable letter from the FDA for Feridex I.V. in
February 1996. After resolving the questions raised by the FDA, the Company must
negotiate final labeling as the last critical step prior to approval for
marketing the product. There can be no assurance that the Company will be able
to satisfactorily resolve the labeling issues raised by the FDA in its
approvable letter. Any failure to satisfactorily resolve labeling issues could
delay FDA approval for marketing Feridex I.V. or could adversely impact the
ability of the Company to market Feridex I.V. Feridex I.V. was approved in
September 1994 by the EU's Committee for Proprietary Medicinal Products and most
of the member states of the EU have issued local approvals to market the
product. Marketing of the product has begun by Guerbet in Europe. Eiken filed an
application for Japanese regulatory approval in March 1994 and expects to
receive an approval for marketing in 1996. Berlex is the Company's exclusive
marketing partner for Feridex I.V. in the United States. See "Licensing and
Marketing Arrangements."
 
     COMBIDEX.  The Company believes that Combidex will be useful in diagnostic
imaging of the liver, spleen and lymphatic system and blood flow in MRA. Lymph
nodes are frequently sites for metastases of different types of cancer,
particularly breast cancer and prostate cancer, and efficient imaging of lymph
nodes could play a major role in determining courses of treatment. There are
currently no available non-invasive methods for distinguishing between lymph
nodes enlarged by tumorous infiltration as opposed to inflammation. Since CT,
the only modality currently used for imaging lymph nodes, cannot distinguish
between enlarged nodes and cancerous nodes, the current practice is to assume
that enlarged nodes are cancerous and to perform a biopsy to establish their
true status. The Company believes that Combidex will enable doctors using MRI to
distinguish between cancerous and noncancerous enlarged lymph nodes because its
accumulation in normal lymph node tissue permits differentiation between normal
and tumor-infiltrated nodes.
 
     The long circulating half-life of Combidex may also permit its use in
analyzing the perfusion, or blood flow, in tissues such as the heart and brain.
Heart attacks and strokes decrease blood flow in damaged tissue, and the Company
believes that Combidex may be useful in delineating the areas of decreased blood
flow or visualizing areas of vascular constriction. The Company also believes
that Combidex can be used to identify tumors in the liver and spleen because
tumors generally have different vascularity than the surrounding tissues.
 
     The Company and Guerbet have completed Phase II clinical trials for the
product in both the United States and Europe for several indications. The
Company has completed patient enrollment for Phase III trials for the product in
the United States for imaging liver lesions and expects to begin separate Phase
III trials for Combidex as a blood flow contrast agent in MRA in 1996. In 1996,
the Company and Guerbet expect to begin Phase III trials for Combidex in the
United States and Europe for imaging of lymph nodes. Phase I trials of Combidex
are scheduled to begin in Japan in 1996.
 
     One of the approximately 475 patients and subjects who were administered
Combidex during its product development suffered an allergic reaction and died
in January 1996. There can be no assurance that this death or any subsequent
death that may occur during the clinical trials for this product would not have
an adverse effect on the Company's ability to continue clinical trials or obtain
regulatory approvals for Combidex or otherwise have a material adverse effect on
the Company's business, financial condition and results of operations. See "Risk
Factors -- Government Regulation; No Assurance of Regulatory Approval," "--
Uncertainties Relating to Clinical Trials; Technological Uncertainty."
 
     The Company has granted exclusive rights to manufacture, market and sell
Combidex in Japan to Eiken and an exclusive right to market and sell Combidex in
Western Europe and Brazil to Guerbet. See "Licensing and Marketing
Arrangements."
 
     GASTROMARK.  MRI imaging of organs and tissues in the abdomen without
contrast agents is difficult because these organs and tissues cannot be easily
distinguished from the loops of the bowel. GastroMARK, the Company's oral
contrast agent for marking of the bowel, when ingested, flows through and
darkens the bowel. By more clearly identifying the intestinal loops, GastroMARK
improves visualization of adjacent abdominal tissues, including the pancreas and
pelvis.
 
     The Company submitted an NDA for GastroMARK with the FDA in November 1993,
which is currently under review by the agency. The Company expects an FDA action
letter during 1996. The Company
 
                                       28

<PAGE>   31
 
has granted Mallinckrodt the exclusive right to co-market GastroMARK in the
United States, Canada and Mexico. The Company has licensed the manufacturing and
marketing rights to GastroMARK on an exclusive basis to Guerbet in Western
Europe and Brazil. During fiscal 1993, Guerbet received marketing approval for
the product in several European countries including France, and marketing of the
product in Europe has begun. In addition, GastroMARK was approved for marketing
in Canada in 1996. See "Licensing and Marketing Arrangements."
 
     OTHER CONTRAST AGENTS UNDER DEVELOPMENT.  The Company is developing
additional contrast agents. The Company believes that a variety of peptides,
antibodies, proteins and polysaccharides may be used to coat its
superparamagnetic iron oxide particles and to target them to specific receptors,
and the Company is currently researching the use of these substances in new
contrast agents. In May 1995, the Company entered into a sponsored research and
license agreement with the General Hospital Corporation, a not-for-profit
Massachusetts corporation doing business as Massachusetts General Hospital
("MGH"). The agreement covers organ-specific, receptor-directed, ultrasmall
superparamagnetic iron oxides for use as MRI contrast agents. The target organ
for the initial collaboration is the pancreas. The Company agreed to pay MGH
$300,000, but payments could exceed this amount depending on milestone
achievements and royalties on future product sales.
 
  TARGETED DRUG DELIVERY PRODUCTS
 
     The Company believes that arabinogalactan will prove useful in delivering
therapeutic pharmaceuticals to the liver because of its lack of toxicity and
high specificity for hepatocytes. The Company expects to begin clinical trials
for the AraAMP conjugate in Europe in 1996. The Company currently expects that
both the manufacturing and clinical testing of the Company's AraAMP conjugate
will initially be performed outside of the United States.
 
     The Company believes that the delivery and use enhancements seen when
AraAMP is attached to arabinogalactan may be obtainable with other therapeutic
agents. The attachment of a variety of therapeutic agents to arabinogalactan,
such as ribavirin and acyclovir, is an active area of research for Advanced
Magnetics and may lead to a series of arabinogalactan-based pharmaceuticals for
the treatment of such liver diseases as hepatitis B, hepatitis C, hepatitis D
and liver cancer.
 
     The Company believes it has a strong intellectual property position
regarding arabinogalactan for use in targeting therapeutic compounds. It has two
United States patents and a notice of allowance for a European patent covering
the delivery of therapeutic agents with arabinogalactan. A third patent covering
the use of arabinogalactan with radiotherapy has issued in the United States.
See "Patents and Trade Secrets."
 
LICENSING AND MARKETING RELATIONSHIPS
 
     The Company's strategy is to enter into corporate alliances to facilitate
the development, marketing and distribution of its contrast agents. These
agreements generally provide for the payment of license fees upon execution and,
in some cases, when the Company or the licensee achieves specified regulatory
milestones. The agreements also provide for royalties based on the licensee's
sales. In certain cases, the Company sells active ingredients or finished
contrast agents to its licensees for payments based on a percentage of sales.
 
     BERLEX.  In February 1995, the Company entered into a license and marketing
agreement and supply agreement with Berlex, granting Berlex exclusive marketing
rights to Feridex I.V. in the United States. The Company is responsible for
performing all work necessary to obtain FDA approval for commercial marketing of
Feridex I.V. in the United States. Under the terms of the agreements, Berlex
paid a $5,000,000 license fee upon execution of the agreements and agreed to pay
an additional $5,000,000 license fee upon the delivery of FDA-approved product
to Berlex. In addition, the Company will receive payments for manufacturing the
agent and royalties on future sales of the agent. These agreements expire in
2010 but are terminable earlier upon specified events such as the determination
by Berlex that the agent is commercially unmarketable due to adverse labeling
requirements imposed by the FDA.
 
                                       29

<PAGE>   32
 
     GUERBET.  In 1987, the Company entered into a supply and distribution
agreement with Guerbet. Under this agreement, Guerbet has been appointed the
exclusive distributor of Feridex I.V. in Western Europe (under the tradename
Endorem) and Brazil. Guerbet is responsible for conducting clinical trials and
securing the necessary regulatory approvals in the countries in its territory.
Guerbet paid the Company license fees of $250,000 in 1987 and $250,000 in 1988
and is required to pay royalties based on sales. The Company is entitled to
receive an additional percentage of Guerbet's sales in return for selling to
Guerbet its requirements for the active ingredient used in the liver contrast
agent. The agreement terminates on the later of (i) the expiration of the last
to expire technology patent or (ii) ten years after the date all necessary
approvals are obtained in France.
 
     In 1989, the Company entered into a second supply and distribution
agreement with Guerbet granting Guerbet an exclusive right in Western Europe
(under the tradename Lumirem) and Brazil to manufacture and sell GastroMARK and
any future Advanced Magnetics MRI contrast agents that Guerbet decides to
market, including Combidex. Under the terms of this second distribution
agreement, Guerbet paid the Company a license fee of $700,000 in 1989. In
addition, Guerbet will pay the Company royalties as a percentage of net sales,
as the purchase price for the active ingredient. The Company is required to sell
to Guerbet its requirements for the active ingredient used in the contrast
agents. The agreement is perpetual but terminable upon specified events such as
non-performance, insolvency or assignment without consent. Also in 1989, Guerbet
purchased 150,000 shares of the Company's common stock at $12.00 per share.
 
     MALLINCKRODT.  In 1990, the Company entered into a manufacturing and
distribution agreement for GastroMARK with Mallinckrodt. Under this agreement,
Mallinckrodt received the exclusive right to manufacture and co-market
GastroMARK in the United States, Canada and Mexico. The Company may also sell
the product through its own direct sales personnel. Mallinckrodt has paid
$1,350,000 under the contract and has agreed to pay $500,000 on FDA approval of
the NDA. Additionally, the Company will receive royalties based on
Mallinckrodt's sales. The Company is required to sell to Mallinckrodt its
requirements of the active ingredient of GastroMARK. The agreement is perpetual
but terminable upon specified events such as non-performance, insolvency or
assignment without consent.
 
     EIKEN.  In 1990, the Company entered into a manufacturing and distribution
agreement with Eiken (the "Eiken Agreement"), granting Eiken the exclusive right
in Japan to manufacture and distribute GastroMARK and Combidex. In addition, for
a period of 180 days after the Company files an NDA for any future Advanced
Magnetics MRI contrast agents, Eiken has the right of first refusal to
manufacture and distribute such product in Japan. Upon execution of this
agreement, Eiken paid the Company a license fee of $1,000,000. Additionally,
Eiken agreed to pay the Company royalties on sales of all products by Eiken
under the agreement. The agreement is perpetual but terminable upon specified
events such as non-performance, insolvency or assignment without consent. Also
in 1990, Eiken purchased 375,000 shares of the Company's common stock for $13.33
per share. Due to market conditions in Japan, Eiken has decided not to market
GastroMARK.
 
     In 1988, the Company entered into a manufacturing and distribution
agreement with Eiken, granting Eiken the exclusive right to manufacture and
distribute Feridex I.V. in Japan. Eiken is responsible for conducting clinical
trials and securing the necessary regulatory approval in Japan. Under the terms
of the agreement as amended, Eiken paid the Company a license fee of $1,150,000
in 1989 and $350,000 in 1990. In addition, Eiken is required to pay royalties
based upon sales. The agreement terminates on the later of (i) the expiration of
the last to expire technology patent or (ii) ten years after the date all
necessary approvals are obtained.
 
     SQUIBB DIAGNOSTICS.  In 1991, the Company entered into agreements with
Squibb Diagnostics, covering certain technology and the manufacturing and
marketing of certain contrast agents including Combidex, which agreements have
been terminated. Under certain circumstances, the Company is obligated to pay
Squibb Diagnostics up to a maximum of $2,000,000 and $2,750,000 in royalties in
connection with product sales of an arabinogalactan receptor-mediated contrast
agent and Combidex, respectively.
 

 

                                       30

<PAGE>   33
 
MANUFACTURING AND SUPPLY ARRANGEMENTS
 
     The Company's Cambridge, Massachusetts facility is registered with the FDA
and is subject to GMP as prescribed by the FDA. The Company currently
manufactures bulk Feridex I.V. product for sale to Guerbet and has developed the
necessary capabilities to manufacture Feridex I.V. finished product for sale to
Berlex and GastroMARK bulk product for sale to Guerbet and Mallinckrodt. The
Company also manufactures Combidex for preclinical and clinical testing by
Guerbet. The Company also expects to utilize contract manufacturers from time to
time if appropriate.
 
     The Company has entered into a manufacturing and supply agreement with
Abbott Laboratories, Inc. ("Abbott"), under which Abbott will manufacture
commercial quantities of Combidex for the Company and Guerbet. The agreement
expires either five years after the Company receives approval to market Combidex
in the United States or if such approval is not obtained in the United States,
the agreement shall terminate in November 2005. Unless terminated earlier by
either party, the agreement automatically renews for five year terms. Either
party may terminate the agreement after the initial five year term upon not less
than two years notice, or on sixty days notice upon bankruptcy or insolvency or
a material breach of the agreement.
 
     Pursuant to the Eiken Agreement, Eiken has the exclusive right in Japan to
manufacture GastroMARK and any of the Company's future contrast agents that it
decides to market pursuant to the Eiken Agreement.
 
     The manufacture of the Company's antiviral therapeutic products will
require the continuous availability of commercial grade arabinogalactan, a
naturally occurring polysaccharide that is commercially available, which the
Company will purify at its Cambridge facility.
 
PATENTS AND TRADE SECRETS
 
     The Company considers the protection of its technology to be material to
its business. The Company's policy is to aggressively protect its competitive
technology position by a variety of means, including applying for patents in the
United States and in appropriate foreign countries. The Company has been granted
21 United States patents and has pending several United States patent
applications covering various aspects of the production of magnetic colloids and
particles, the composition of particles, the formulation of colloids and certain
applications of these colloids and particles. The Company has filed counterpart
patent applications in several foreign countries. In addition, the Company is a
party to various license agreements, including non-exclusive cross-licensing
arrangements covering MRI imaging technology with Nycomed and Schering. The
Company's proprietary position depends in part on these licenses, and
termination of the licenses for any reason could have a material adverse effect
on the Company by limiting or prohibiting the commercial sale of its products.
Although the Company believes that further patents will be issued on pending
applications, no assurance to this effect can be given.
 
     The patent positions of pharmaceutical and biopharmaceutical firms,
including Advanced Magnetics, are generally uncertain and involve complex legal
and factual questions. There can be no assurance that any claims which are
included in pending or future patent applications will be issued, that any
issued patents will provide the Company with competitive advantages or will not
be challenged by others, or that the existing or future patents of third parties
will not be have an adverse effect on the ability of the Company to
commercialize its products.
 
     One of the Company's MRI patents is the subject of two interference
proceedings in the U.S. Patent Office. The Company has a non-exclusive license
to the patent applications involved in one of these interference proceedings,
which applications are owned by Nycomed and Schering. Because the Company does
not currently have rights in all the patents and patent applications which are
the subject of the other interference, there can be no assurance that the
outcome of that interference will not have an outcome with a material adverse
effect on the Company. There can be no assurance that future patent
interferences involving patents of either the Company or its licensors will not
have a material adverse effect on the Company's business. Moreover, there can be
no assurance that claims of infringement or violation of the proprietary rights
of others will not be asserted against the Company. If Advanced Magnetics is
required to defend against such
 
                                       31

<PAGE>   34
 
claims or to protect its own proprietary rights against others, the Company may
incur substantial costs which could have a material adverse effect on the
Company's business, financial condition and results of operations.
 
     The Company believes it has a strong intellectual property position
regarding arabinogalactan for use in targeting therapeutic compounds. It has two
U.S. patents and a notice of allowance for a European patent covering the
delivery of therapeutic agents with arabinogalactan. A third patent covering the
use of arabinogalactan with radiotherapy has issued in the United States.
Additional therapeutic applications are pending, but there is no assurance that
any additional patents will issue to the Company.
 
     The Company also intends to rely on its trade secrets, know-how, continuing
technological innovations and licensing opportunities to maintain and develop
its competitive position. Although the Company seeks to protect its proprietary
information, there can be no assurance that others will not independently
develop the same or similar information, design around the patents, obtain
unauthorized access to the Company's proprietary information or misuse
information to which the Company has granted access. Litigation may be necessary
to enforce any patents issued to the Company or to determine the scope of other
person's proprietary rights in court or administrative proceedings. Any
litigation or administrative proceeding could result in substantial costs to the
Company and distraction of the Company's management. An adverse ruling in any
litigation or administrative proceeding could have a material adverse effect on
the Company's business, financial condition and results of operations.
 
COMPETITION
 
     The pharmaceutical and biopharmaceutical industries are subject to intense
competition and rapid technological change. While there are currently no MRI
contrast agents designed for organ-specific applications marketed in the United
States other than chelated gadolinium compounds for imaging the central nervous
system, the Company expects competition in the development of new MRI contrast
agents to increase substantially. Certain companies, including the Company's
collaborators, which have greater human and financial resources dedicated to
product development and clinical testing than the Company, are developing MRI
contrast agents. The Company's collaborators are not restricted from developing
and marketing competing products and as a result of certain cross license
agreements among the Company and certain of its competitors (including some of
its collaborators), the Company's competitors will be able to utilize certain of
the Company's technology in the development of competing products. There can be
no assurance that the Company will be able to compete successfully with these
companies.
 
     The Company believes that its ability to compete successfully in the MRI
contrast agent market will depend on a number of factors including the
development of efficacious products, timely receipt of regulatory approvals and
product manufacturing at commercially acceptable costs. In addition, the
Company's MRI contrast agents represent a new approach to imaging certain organs
and market acceptance of both MRI as an appropriate technique for such organs
and the Company's products is critical to the success of its contrast agent
products. Although the Company believes that its contrast agents will offer
advantages over competing MRI, CT or X-ray contrast agents, there can be no
assurance that there will be greater acceptance of its products over other
contrast agents. In addition, to the extent that other diagnostic techniques
such as CT and X-ray may be perceived as providing greater value than MRI, any
corresponding decrease in the use of MRI would have an adverse effect on the
demand for the Company's contrast agent products. There can be no assurance that
the Company will be able to successfully develop efficacious products, obtain
timely regulatory approvals, manufacture products at commercially acceptable
costs, gain satisfactory market acceptance or otherwise successfully compete in
the future.
 
     There are several MRI contrast agents for imaging lesions of the liver in
various phases of human testing in the United States and abroad. Schering has
two products in development, Resovist, a carboxydextran superparamagnetic iron
oxide formulation, and Eovist, a chelated gadolinium compound. The Company
believes that Resovist is in Phase III trials in Europe and Japan and that
Eovist has completed Phase II trials in Europe. Nycomed has filed an NDA for its
MnDPDP product in the United States and Europe for MRI of liver lesions. The
Company believes that Bracco S.p.A. is conducting Phase II trials in Europe for
Gadolinium BOPTA, another chelated gadolinium compound. In the area of oral
contrast agents, Pharmacyclics, Inc. filed
 
                                       32

<PAGE>   35
 
an NDA in late 1995 for GADOLITE, its gadolinium-based product candidate, and
Bracco S.p.A. has filed an NDA in the United States for Lumenhance, its
liposomal encapsulated oral manganese compound. The Company believes that
Feridex I.V. and GastroMARK are more advanced in the clinical approval process
than these competitive products and believes that being first to market with a
safe and effective product is a major competitive advantage. There can be no
assurance, however, that these competitive products or new products developed by
the Company's competitors will not be more effective than any products developed
by the Company or render the Company's technology obsolete.
 
     Many companies, including large pharmaceutical, chemical and biotechnology
companies, and academic and research institutions are engaged in developing
vaccines and products for therapeutic use for treatment of hepatitis B and C.
Both Hoffman-LaRoche and Schering-Plough have interferon products approved in
the United States and elsewhere for use against hepatitis B. Glaxo Wellcome's
Lamivudine, already approved for use in AIDS patients, is in Phase III trials
for hepatitis B around the world, and Sciclone Pharmaceuticals is conducting
Phase III trials for Zadaxine in Taiwan for hepatitis B. Other competitors
developing hepatitis B therapeutics include Biogen, SmithKline Beecham, Gilead
Sciences and ICN Pharmaceuticals. Therapeutic candidates for hepatitis C are
being developed by Hoffman-LaRoche, Schering-Plough, ICN Pharmaceuticals, Biogen
and Agouron.
 
     Many of these companies have substantially greater capital, research and
development, manufacturing and marketing resources and experience than the
Company and represent significant competition for Advanced Magnetics. Such
companies may succeed in developing technologies and products that are more
effective or less costly than any that may be developed by the Company and may
also prove to be more successful than the Company in production and marketing.
There can be no assurance that Advanced Magnetics will successfully develop its
proposed drug delivery products, obtain required regulatory approvals or gain
satisfactory market acceptance for such products. Furthermore, there can be no
assurance that these products or new products developed by the Company's
competitors will not be more effective than any products developed by the
Company or render the Company's technology obsolete. The Company believes,
however, that no one therapeutic will be effective for all patients and that low
production costs will be a significant determinant of future success in the
worldwide marketplace.
 
GOVERNMENT REGULATION AND REIMBURSEMENT
 
     The production and marketing of the Company's products and its ongoing
research and development activities are subject to regulation for safety,
efficacy and quality by numerous governmental authorities in the United States
and other countries. Pharmaceutical products intended for therapeutic use in
humans are principally governed by FDA regulations in the United States and by
comparable government regulations in foreign countries. Various federal, state
and local statutes and regulations also govern or influence the research and
development, manufacturing, safety, labeling, storage, recordkeeping,
distribution and marketing of such products. The process of completing
preclinical and clinical testing and obtaining the approval of the FDA and
similar health authorities in foreign countries to market a new drug product
requires a significant number of years and the expenditure of substantial
resources. To date, no contrast agent based on magnetic particles has been
approved by the FDA, although the Company has received an approvable letter for
Feridex I.V. Failure to obtain requisite governmental approvals or failure to
obtain approvals of the scope requested will delay or preclude the Company or
its licensees or collaborators from marketing the Company's products or limit
the commercial use of the products and will have a material adverse effect on
the Company's business, financial condition and results of operations.
 
     The steps required by the FDA before a new human pharmaceutical product,
including a contrast agent or therapeutic drug, may be marketed in the United
States include: (a) preclinical laboratory tests, in vivo preclinical studies
and formulation studies; (b) the submission to the FDA of a request for
authorization to conduct clinical trials subject to an Investigational New Drug
("IND") exemption, to which the FDA must not object, before human clinical
trials may commence; (c) adequate and well-controlled human clinical trials to
establish the safety and efficacy of the drug for its intended use; (d)
submission to the FDA of an NDA; (e) approval and validation of manufacturing
facilities and production uses of the pharmaceutical; and
 
                                       33

<PAGE>   36
 
(f) review and approval of the NDA by the FDA before the drug product may be
shipped or sold commercially.
 
     Preclinical tests include the laboratory evaluation of product chemistry
and formulation, as well as animal studies to assess the potential safety and
efficacy of the product. Preclinical test results are submitted to the FDA as a
part of the IND. Clinical trials are typically conducted in three sequential
phases, although the phases may overlap. Phase I involves the initial
administration of the drug to a small group of humans, either healthy volunteers
or patients, to test for safety, dosage tolerance, absorption, distribution,
metabolism, excretion and clinical pharmacology and, if possible, early
indications of effectiveness. Phase II involves studies in a small sample of the
actual intended patient population to assess the preliminary efficacy of the
investigational drug for a specific clinical indication, to ascertain dose
tolerance and the optimal dose range and to collect additional clinical
information relating to safety and potential adverse effects. Once an
investigational drug is found to have some efficacy and an acceptable clinical
safety profile in the targeted patient population, Phase III studies can be
initiated to further establish safety and efficacy of the investigational drug
in a broader sample of the target patient population. The results of the
clinical trials together with the results of the preclinical tests and complete
manufacturing information are submitted in an NDA to the FDA for approval. The
FDA may suspend clinical trials at any point in this process if it concludes
that patients are being exposed to an unacceptable health risk.
 
     If an NDA is submitted to the FDA, there can be no assurance that such
application will be reviewed and approved by the FDA in a timely manner, if at
all. Even after initial FDA approval has been obtained, further studies,
including post-market studies, may be required to provide additional
information. Results of such post-market programs may limit or expand the
further marketing of the product. Even if initial marketing approval is granted,
such approval may entail limitations on the indicated uses for which a product
may be used and impose labeling requirements which may adversely impact the
Company's ability to market its products. Finally, product approvals may be
withdrawn if compliance with regulatory standards is not maintained or if
problems occur following initial marketing.
 
     Among the conditions for NDA approval is the requirement that a prospective
manufacturer's manufacturing procedures conform to GMP requirements, which must
be followed at all times. In complying with those requirements, manufacturers
(including a drug sponsor's third-party contract manufacturers) must continue to
expend time, money and effort in the area of production and quality control to
ensure compliance. Domestic manufacturing establishments are subject to periodic
inspections by the FDA in order to assess, among other things, GMP compliance.
To supply product for use in the United States, foreign manufacturing
establishments must comply with GMP and are subject to periodic inspection by
the FDA or by regulatory authorities in certain of such countries under
reciprocal agreements with the FDA. Failure to maintain compliance with GMP
regulations and other applicable manufacturing requirements of various
regulatory agencies could have a material adverse effect on the Company's
business, financial condition and results of operations.
 
     The Company is also subject to foreign regulatory requirements governing
development, manufacturing and sales of pharmaceutical products that vary widely
from country to country. Approval of a drug by applicable regulatory agencies of
foreign countries must be secured prior to the marketing of such drug in those
countries. The regulatory approval process may be more or less rigorous from
country to country and the time required for approval may be longer or shorter
than that required in the United States.
 
     The Company is and may be subject to regulation under local, state and
Federal law regarding occupational safety, laboratory practices, handling of
chemicals, environmental protection and hazardous substances control. The
Company possesses a By-product Materials License from the Nuclear Regulatory
Commission ("NRC") for receipt, possession, manufacturing and distribution of
radioactive materials. The Company holds Registration Certificates from the
United States Drug Enforcement Administration and the Commonwealth of
Massachusetts Department of Public Health for handling controlled substances.
The Company is registered with the United States Environmental Protection Agency
("EPA") as a generator of hazardous waste. All hazardous waste disposal must be
made in accordance with EPA and NRC require-
 
                                       34

<PAGE>   37
 
ments. The Company is subject to the regulations of the Occupational Safety and
Health Act and has in effect a safety program to assure compliance with these
regulations.
 
     In both the United States and foreign markets, the Company's ability to
commercialize its products successfully also depends in part on the extent to
which reimbursement for the costs of such products and related treatments will
be available from government health administration authorities, private health
insurers and other third-party payors. In the United States, there has been, and
the Company expects that there will continue to be, a number of federal and
state proposals to reform the health care system. In addition, an increasing
emphasis on managed care in the United States has and will continue to put
pressure on pharmaceutical pricing. Such initiatives and proposals, if adopted,
could decrease the price that the Company receives for its existing products, as
well as any products it may develop and sell in the future. Significant
uncertainty exists as to the reimbursement status of newly approved health care
products and products used for indications not approved by the FDA. If adequate
reimbursement levels are not maintained by government and other third-party
payors for the Company's products and related treatments, the Company's
business, financial condition and results of operations may be materially
adversely affected.
 
EMPLOYEES
 
     As of February 9, 1996, the Company had approximately 64 full-time
employees, 53 of whom were engaged in research and development. The Company's
success depends in part on its ability to recruit and retain talented and
trained scientific personnel. The Company has been successful to date in
obtaining such personnel, but there can be no assurance that such success will
continue.
 
PRODUCT LIABILITY INSURANCE
 
     The use of any of the Company's potential products in clinical trials and
the sale of any approved products may expose the Company to liability claims
resulting from the use of products or product candidates. These claims might be
made by customers (including corporate partners), clinical trial subjects,
patients, pharmaceutical companies or others. The Company maintains product
liability insurance coverage for claims arising from the use of its products in
clinical trials. However, coverage is becoming increasingly expensive and no
assurance can be given that the Company will be able to maintain insurance at a
reasonable cost. There can be no assurance that the Company's insurance will
provide sufficient amounts to protect the Company against losses due to
liability that could have a material adverse effect on the Company's business,
financial conditions and results of operations. The Company does not presently
maintain product liability insurance covering the sale of its products approved
for commercial marketing and there can be no assurance that the Company will be
able to obtain commercially reasonable product liability insurance for any
product presently being marketed or for any product approved for marketing in
the future or that insurance coverage and the resources of the Company would be
sufficient to satisfy any liability resulting from product liability claims. A
product liability claim or series of claims brought against the Company could
have a material adverse effect on its business, financial condition and results
of operations, whether or not the plaintiffs in such claims ultimately prevail.
See "Risk Factors -- Potential Product Liability; Uncertainties Related to
Insurance."
 
FACILITIES
 
     The Company's principal pharmaceutical manufacturing and research and
development operations are located in a modern Company-owned building of
approximately 25,000 square feet in Cambridge, Massachusetts, which includes a
recently completed 3,800 square-feet expansion. The Company has leased two
additional premises in Cambridge of approximately 18,000 total square feet to be
used for manufacturing, warehousing and executive office space. One lease
expires on October 31, 1997 and the other lease expires on December 31, 1997. In
addition, the Company has leased premises of approximately 5,200 square feet in
Princeton, New Jersey used by the Company's clinical development group as a
general business, sales and administrative office. This lease expires on
September 30, 1996 but includes two one year extension options. The Company
believes these facilities are adequate for its current and anticipated
short-term needs and that it will be able to enter into lease extensions or to
lease comparable space, if necessary. However, the acquisition and required
regulatory approvals for additional pharmaceutical manufacturing space can be
time consuming
 
                                       35

<PAGE>   38
 
and expensive. There is no assurance that if the Company desired to expand its
manufacturing capacity it would be able to do so on a timely basis, if at all.
 
LEGAL PROCEEDINGS
 
     The Company and certain of its officers were sued in an action entitled
David D. Stark, M.D. v. Advanced Magnetics, Inc., Jerome Goldstein, Ernest V.
Groman, and Lee Josephson, Civil Action No. 92-12157-WGY, in the United States
District Court for the District of Massachusetts on September 3, 1992. The
plaintiff, a former consultant to the Company, claims that he was incorrectly
omitted as an inventor or joint inventor on certain of the Company's patents and
on pending applications, and seeks injunctive relief and unspecified damages. In
addition, the complaint also alleges state law claims for breach of contract,
breach of good faith and fair dealing, breach of implied contract,
misappropriation of trade secrets, conversion, negligent misrepresentation,
misrepresentation, unjust enrichment and unfair trade practices. The District
Court has held that the plaintiff cannot succeed on both his claims to correct
inventorship under federal law and his state law claims as these claims are
mutually exclusive. The plaintiff recently appealed the District Court's
analysis of the federal law to the United States Court of Appeals for the
Federal Circuit. While the outcome of the action cannot be determined, the
Company believes the action is without merit and intends to defend the action
vigorously if it is reopened. There can be no assurance, however, that the
Company will be able to successfully defend this action and the failure by the
Company to prevail for any reason could have an adverse effect on the Company's
future business, financial condition and results of operations.
 
     The Company and certain of its officers were sued in David D. Stark v.
Advanced Magnetics, Inc., Jerome Goldstein, Ernest V. Groman and Lee Josephson,
Civil Action No. 93-02846-C, in the Superior Court Department of the
Massachusetts Trial Court for Middlesex County. This case involves claims of
breach of contract, breach of good faith and fair dealing, breach of implied
contract, unjust enrichment and unfair trade practices that were originally
dismissed by, but later remanded to, the Federal Court in the above-mentioned
action, as well as a new count alleging tortious interference with contractual
or advantageous relations. The Superior Court granted partial summary judgment
in the Company's favor and dismissed the unfair trade practices and tort counts.
The Superior Court has stayed the action until May 17, 1996. While the outcome
of the action cannot be determined, the Company believes the action is without
merit and intends to defend the action vigorously. There can be no assurance,
however, that the Company will be able to successfully defend this action and
the failure by the Company to prevail for any reason could have an adverse
effect on the Company's future business, financial condition and results of
operations.
 
                                       36

<PAGE>   39
 
                                   MANAGEMENT
 
EXECUTIVE OFFICERS AND DIRECTORS


<TABLE>
     The directors and executive officers of the Company are as follows (1):
 
<CAPTION>
                NAME                   AGE                      POSITION
                ----                   ---                      --------
<S>                                    <C>     <C>
Jerome Goldstein.....................   56     Chairman of the Board of Directors, Chief
                                               Executive Officer, President and
                                               Treasurer(2)
Lee Josephson, Ph.D..................   50     Senior Vice President -- Research
Leonard M. Baum......................   42     Senior Vice President
Anthony P. Annese....................   66     Vice President -- Finance
Paula M. Jacobs, Ph.D................   51     Vice President -- Development
Jerome M. Lewis, Ph.D................   47     Vice President -- Scientific Operations
Mark C. Roessel......................   45     Vice President -- Regulatory Affairs
Thomas Coor, Ph.D....................   73     Director
Leslie Goldstein.....................   61     Director
Richard L. McIntire..................   61     Director
Edward B. Roberts, Ph.D..............   60     Director(2)
Roger E. Travis......................   58     Director(2)
George M. Whitesides, Ph.D...........   56     Director
<FN>
 
- ---------------
(1) The Board of Directors is responsible for establishing and administering the
    Company's executive compensation programs.
 
(2) Member of Audit Committee.
</TABLE>

 
     Jerome Goldstein is a founder of the Company and has been Chairman of the
Board of Directors, Chief Executive Officer, President and Treasurer since the
Company's organization in November 1981.
 
     Lee Josephson, Ph.D. is a founder of the Company and has been Senior Vice
President -- Research since November 1990.
 
     Leonard M. Baum joined the Company in October 1994 as a Senior Vice
President. From 1986 to 1994, Mr. Baum was Senior Director, Worldwide Regulatory
Affairs/Drug Safety at Squibb Diagnostics.
 
     Anthony P. Annese joined the Company in December 1987 as Vice
President -- Finance.
 
     Paula M. Jacobs, Ph.D. joined the Company in January 1986 as Vice
President -- Development.
 
     Jerome M. Lewis, Ph.D. joined the Company in April 1986 as a Senior
Scientist and has been Vice President -- Scientific Operations since February
1991.
 
     Mark C. Roessel joined the Company in January 1982 as a Director of
Regulatory Affairs and has been Vice President -- Regulatory Affairs since
January 1995.
 
     Thomas Coor, Ph.D. has been a director of the Company since 1983. Dr. Coor
is currently a consultant. Dr. Coor is also a director of Aston, Inc., a
developer of specialty biochemicals.
 
     Leslie Goldstein has been a director of the Company since 1981. Mr.
Goldstein has been an associate of SRG Associates, a division of Fahnestock &
Co., Inc., since 1977. Mr. Goldstein is the brother of Jerome Goldstein.
 
     Richard L. McIntire has been a director of the Company since 1982. Mr.
McIntire is Chairman of the Board of Marketing Information Services, Inc., a
developer of computer software, and has been the Chairman of Vantage Capital
Group, an investment and consulting firm, since 1990.
 
                                       37

<PAGE>   40
 
     Edward B. Roberts, Ph.D. has been a director of the Company since 1982.
Professor Roberts has been Professor at the Sloan School at MIT since 1961. He
is a co-founder and was Chairman of Pugh-Roberts Associates, Inc., a management
consulting firm that is now a division of PA Consulting Group, Inc. Professor
Roberts is also a general partner of Zero Stage Capital Management, L.P., a
venture capital limited partnership.
 
     Roger E. Travis has been a director of the Company since its organization
in 1981. He is currently President of Roger E. Travis Associates, a small
business consulting firm founded by him in 1978.
 
     George M. Whitesides, Ph.D. has been a director of the Company since 1981.
Professor Whitesides has been a Professor of Chemistry at Harvard University
since 1982. He is a director of Dexter Corporation, a manufacturer of specialty
material products.
 
     Officers and directors are elected on an annual basis. The present term of
office for each director will expire at the next annual meeting of the Company's
stockholders or at such time as his successor is duly elected. Officers serve at
the discretion of the Board of Directors.
 
                                       38

<PAGE>   41

<TABLE>
                       PRINCIPAL AND SELLING STOCKHOLDERS
 
     The following table sets forth information with respect to the beneficial
ownership of the Company's Common Stock as of March 13, 1996 and as adjusted to
reflect the Offering, by (i) by each person known by the Company to be the
beneficial owner of more than 5% of the outstanding Common Stock, (ii) each
director of the Company, (iii) all officers and directors as a group and (iv)
the Selling Stockholders. Unless otherwise indicated below, to the knowledge of
the Company, all persons listed below have sole voting and investment power with
respect to their shares of Common Stock, except to the extent authority is
shared by spouses under applicable law.
 
<CAPTION>
                                                                                       SHARES TO BE
                                                  SHARES BENEFICIALLY                  BENEFICIALLY
                                                    OWNED PRIOR TO                      OWNED AFTER
                                                      OFFERING(1)       NUMBER OF     OFFERING(1)(2)
                                                  -------------------    SHARES     -------------------
                                                   NUMBER     PERCENT    OFFERED     NUMBER     PERCENT
                                                  ---------   -------   ---------   ---------   -------
<S>                                                 <C>         <C>       <C>         <C>          <C>
DIRECTORS, OFFICERS AND 5% STOCKHOLDERS:
Jerome Goldstein(3)(4)(5).......................    689,422     10.2%     50,000      639,422      8.1%
Marlene Kaplan Goldstein(3)(5)..................    683,137     10.1%     62,017      621,120      7.9%
Eiken Chemical Co., Ltd. .......................    375,000      5.5%         --      375,000      4.8%
  1-33-8 Hongo
  Bunkyo-Ku
  Tokyo, Japan
Lee Josephson, Ph.D.(6).........................    156,980      2.3%     24,483      131,963      1.7%
Paula M. Jacobs, Ph.D.(7).......................     23,518       *        3,000       20,518       *
Jerome M. Lewis, Ph.D.(8).......................     13,135       *        3,000       10,135       *
Leonard M. Baum(9)..............................      5,000       *           --        5,000       *
Leslie Goldstein(10)............................    330,250      4.9%     27,500      302,750      3.8%
  SRG Associates
  805 Third Avenue
  New York, New York
Thomas Coor, Ph.D.(11)..........................     27,000       *           --       27,000       *
Richard L. McIntire(11)(12).....................    110,500      1.6%         --      110,500      1.4%
Edward B. Roberts, Ph.D.(11)(13)................    109,500      1.6%         --      109,500      1.4%
Roger E. Travis(14).............................     35,361       *           --       32,361       *
George M. Whitesides, Ph.D.(11).................     74,500      1.1%         --       74,500       *
All executive officers and directors as a group
  (14 persons)(15)..............................  2,294,861     33.2%    170,000    2,124,861     26.7%

OTHER SELLING STOCKHOLDERS:
Ernest V. Groman, Ph.D.(16) ....................    125,000      1.8%     25,000      100,000      1.5%
Rachel Goldstein................................     62,865       *       15,000       47,865       *
Lisa Goldstein..................................     62,865       *       15,000       47,865       *
Guerbet, S.A. ..................................    150,000      2.2%     25,000      125,000      1.6%
  Boite Postale 50400
  95543 Rolssy C6G
  Codex - France
<FN>
- ---------------
  *  Less than 1% of the outstanding Common Stock.
 
 (1) The number of shares of Common Stock deemed outstanding includes 6,766,642
     shares of Common Stock outstanding as of March 13, 1996. The number of
     shares of Common Stock deemed outstanding after the Offering includes an
     additional 1,100,000 shares of Common Stock being offered for sale by the
     Company in the Offering. Each person has sole voting and investment power
     with respect to all shares of Common Stock shown as beneficially owned,
     except as otherwise indicated.
 
 (2) The number of shares of Common Stock offered and the number of shares of
     Common Stock beneficially owned after the Offering do not give effect to
     the Underwriters' over-allotment option. All of
</TABLE>

                                       39

<PAGE>   42
 
     the shares of Common Stock to be sold pursuant to the over-allotment option
     will be sold by the Company.
 
 (3) Jerome Goldstein and Marlene Kaplan Goldstein are husband and wife but each
     disclaims control or beneficial ownership of shares held by the other. The
     address of each is c/o Advanced Magnetics, Inc., 725 Concord Avenue,
     Cambridge, Massachusetts 02138.
 
 (4) Includes 7,500 shares issuable to Jerome Goldstein pursuant to options
     exercisable on or before May 14, 1996 and 13,500 shares held by the Kaplan
     Goldstein Family Foundation, a charitable foundation whose trustees are
     Jerome Goldstein, Marlene Kaplan Goldstein and their two adult children.
 
 (5) Excludes 125,730 shares held by the children of Jerome Goldstein and
     Marlene Kaplan Goldstein, as to which shares each of Jerome Goldstein and
     Marlene Kaplan Goldstein disclaims beneficial ownership.
 
 (6) Includes 7,500 shares issuable to Dr. Josephson pursuant to options
     exercisable on or before May 14, 1996. Includes 15,074 shares, as to which
     shares Dr. Josephson disclaims beneficial ownership, held by the children
     of Dr. Josephson.
 
 (7) Includes 12,750 shares issuable to Dr. Jacobs pursuant to options
     exercisable on or before May 14, 1996 and 1,843 shares held in custodial
     accounts for her children.
 
 (8) Includes 9,500 shares issuable to Dr. Lewis pursuant to options exercisable
     on or before May 14, 1996. All of the shares offered are held in joint
     tenancy with Dr. Lewis' wife.
 
 (9) Includes 5,000 shares issuable to Mr. Baum pursuant to options exercisable
     on or before May 14, 1996.
 
(10) Includes 21,750 shares held by Leslie Goldstein for the following
     charitable foundation and trusts: 3,750 shares held by him as Trustee of
     the Allan Goldstein Children's Trust, 3,000 shares held by him as Trustee
     for his children and 15,000 shares held by him as Trustee of the Leslie and
     Roslyn Goldstein Foundation. Includes 1,500 shares, as to which Mr.
     Goldstein disclaims beneficial ownership, owned by Mr. Goldstein's wife.
     Does not include 191,206 shares held in certain investment accounts over
     which Mr. Goldstein exercises limited investment discretion. Mr. Goldstein
     has relinquished any rights to exercise investment discretion over such
     shares and accordingly disclaims beneficial ownership of such shares.
 
(11) Includes 14,500 shares issuable under currently exercisable options granted
     to each non-employee director.
 
(12) Includes 50,600 shares held in joint tenancy with Mr. McIntire's wife.
 
(13) Includes 34,500 shares held by Dr. Roberts as trustee for his children.
 
(14) Includes 8,000 shares, as to which Mr. Travis disclaims beneficial
     ownership of 3,000 shares, held by Mr. Travis as custodian for his
     children, and includes 7,000 shares issuable under currently exercisable
     options granted to Mr. Travis in his capacity as a non-employee director.
 
(15) Includes 79,593 shares held in family trusts and custodial accounts for
     various directors' and officers' children and 148,440 shares issuable under
     options exercisable on or before May 14, 1996.
 
(16) All of the shares offered are held in joint tenancy with Dr. Groman's wife.
 
                                       40

<PAGE>   43
 
                          DESCRIPTION OF CAPITAL STOCK
 
     The Company's authorized capital stock consists of 15,000,000 shares of
Common Stock and 2,000,000 shares of Preferred Stock, $.01 par value per share
("Preferred Stock").
 
COMMON STOCK
 
     Holders of Common Stock are entitled to one vote per share on matters to be
voted upon by the stockholders. Holders of Common Stock do not have cumulative
voting rights, which means that the holders of more than half of the shares can
elect all the directors and, in that event, the holders of the remaining shares
cannot elect any directors. Holders of Common Stock are entitled to receive
dividends when and as declared by the Board of Directors and to share ratably in
the assets of the Company legally available for distribution to stockholders in
the Company. Holders of Common Stock have no preemptive, subscription,
redemption or conversion rights. All outstanding shares of Common Stock are, and
the shares to be sold in the Offering, upon issuance and payment therefor, will
be, validly issued, fully paid and nonassessable.
 
     As of March 14, 1996, there were 6,766,642 shares of Common Stock
outstanding, held by approximately 303 stockholders of record.
 
PREFERRED STOCK
 
     The Board of Directors is authorized to issue the Preferred Stock in
different series and classes and to fix the dividend rights, dividend rate,
conversion rights, voting rights, rights and terms of redemption (including
sinking fund provisions), liquidation preferences and other rights and
preferences of the Preferred Stock not in conflict with the Company's
Certificate of Incorporation. There are currently no shares of Preferred Stock
outstanding. The Board of Directors, without stockholder approval, can issue
Preferred Stock with voting and conversion rights that could adversely affect
the voting power of holders of Common Stock. The issuance of Preferred Stock may
have the effect of delaying, deferring or preventing a change in control of the
Company. The Company has no present plans to issue any shares of Preferred
Stock.
 
DELAWARE LAW AND CERTAIN CHARTER PROVISIONS
 
     The Company is subject to the provisions of Section 203 of Delaware General
Corporation Law. That section generally provides, with certain exceptions, that
a Delaware corporation may not engage in any of a broad range of business
combinations with a person or affiliate, or associate of such person, who is an
"interested stockholder" for a period of three years from the date that such
person became an interested stockholder unless the transaction is approved in a
prescribed manner. An "interested stockholder" is defined as any person that is
(i) the owner of 15% or more of the outstanding voting stock of the corporation
or (ii) an affiliate or associate of the corporation and was the owner of 15% or
more of the outstanding voting stock of the corporation at any time within the
three-year period immediately prior to the date on which it is sought to be
determined whether such person is an interested stockholder.
 
     The Company's Certificate of Incorporation contains certain provisions
permitted under the Delaware General Corporation Law relating to the liability
of directors. The provisions eliminated the directors' liability for monetary
damages for a breach of fiduciary duty, except in certain circumstances
involving wrongful acts, including the breach of a director's duty of loyalty or
acts or omissions which involve intentional misconduct or a knowing violation of
a law. The Company's Certificate of Incorporation also contains provisions to
indemnify its directors and officers to the fullest extent permitted by the
Delaware General Corporation Law. The Company believes that these provisions
will assist the Company in attracting or retaining qualified individuals to
serve as directors.
 
TRANSFER AGENT
 
     The Transfer Agent and the Registrar for shares of the Company's Common
Stock is Boston Equiserve, L.P., 100 Federal Street, Boston, Massachusetts
02110.
 
                                       41

<PAGE>   44
 
                                  UNDERWRITING
 
     Upon the terms and subject to the conditions of the Underwriting Agreement
(the "Underwriting Agreement") among the Company and the Underwriters named
below (the "Underwriters"), for whom PaineWebber Incorporated, Donaldson, Lufkin
& Jenrette Securities Corporation, Oppenheimer & Co., Inc. and Tucker Anthony
Incorporated are acting as representatives (the "Representatives"), the
Underwriters severally have agreed to purchase from the Company and the Selling
Stockholders, and the Company and the Selling Stockholders have agreed to sell
to the Underwriters severally, 1,350,000 shares of Common Stock, which in the
aggregate equal the number of shares set forth opposite the names of such
Underwriters below:
 

<TABLE>
<CAPTION>
           UNDERWRITER                                                    NUMBER OF SHARES
           -----------                                                    ----------------
    <S>                                                                        <C>
    PaineWebber Incorporated.............................................
    Donaldson, Lufkin & Jenrette
      Securities Corporation.............................................
    Oppenheimer & Co., Inc. .............................................
    Tucker Anthony Incorporated..........................................
 
                                                                               ---------
              Total......................................................      1,350,000
                                                                               =========
</TABLE>

 
     In the Underwriting Agreement, the several Underwriters have agreed,
subject to certain conditions, to purchase all of the shares of Common Stock
being sold pursuant to such Agreement (other than those covered by the
over-allotment option described below), if any are purchased. The Underwriting
Agreement provides that, in the event of a default by an Underwriter, in certain
circumstances, the purchase commitments of non-defaulting Underwriters may be
increased or the Underwriting Agreement may be terminated.
 
     The Company has been advised by the Representatives that the Underwriters
propose to offer the shares of Common Stock in part to the public at the price
to the public set forth on the cover page of this Prospectus, and in part to
certain securities dealers (who may include the Underwriters) at such price less
a concession not in excess of $          per share; and that the Underwriters
and such dealers may reallow a discount not in excess of $          per share of
other dealers, including the Underwriters. After the commencement of the public
offering, the public offering price, the concession to selected dealers and the
discounts to other dealers may be changed by the Representatives.
 
     The Company has granted to the Underwriters an option, exercisable during
the 30 day period after the date of this Prospectus, under which the
Underwriters may purchase up to 202,500 additional shares of Common Stock from
the Company at the price to the public set forth on the cover page of this
Prospectus, less the underwriting discounts and commissions. The Underwriters
may exercise the option solely for the purpose of covering over-allotments, if
any, made in connection with the offering of the Shares. To the extent that such
option is exercised, each of the Underwriters will become obligated, subject to
certain conditions, to purchase approximately the same percentage of such
additional shares of Common Stock as it was obligated to purchase pursuant to
the Underwriting Agreement.
 
     The Company and the Selling Stockholders have agreed to indemnify the
Underwriters against certain liabilities, including liabilities under the
Securities Act, or to contribute to payments the Underwriters may be required to
make in respect thereof.
 
     The Company, the Selling Stockholders and certain other stockholders of the
Company, including the officers and directors who are not Selling Stockholders,
have agreed not to (1) offer to sell, sell, contract to sell or otherwise
dispose of any shares of Common Stock or rights to acquire shares of Common
Stock or (2) enter into any swap or similar agreement that transfers, in whole
or in part, any of the economic consequences of the ownership of shares of
Common Stock during the 90 day period following the date of this
 
                                       42

<PAGE>   45
 
Prospectus, without in each case the prior written consent of PaineWebber
Incorporated, other than (i) shares to be sold to the Underwriters in the
Offering, (ii) shares of Common Stock to be issued upon the exercise of
outstanding options or otherwise under employee benefit plans, including under
incentive stock and option plans of the Company, (iii) shares of Common Stock to
be issued upon the exercise of outstanding warrants, and (iv) shares of Common
Stock issuable in connection with acquisitions by the Company provided that such
shares are not eligible for resale during the 90 day period following the date
of this Prospectus.
 
                                 LEGAL MATTERS
 
     The validity of the shares of Common Stock offered hereby will be passed
upon for the Company by Testa, Hurwitz & Thibeault, Boston, Massachusetts.
Certain legal matters in connection with this offering will be passed upon for
the Underwriters by Shearman & Sterling, New York, New York.
 
                                    EXPERTS
 
     The balance sheets as of September 30, 1994 and 1995 and the related
statements of operations, stockholders' equity (deficit) and cash flows for each
of the three years in the period ended September 30, 1995 of the Company
included and incorporated by reference in this Prospectus and the Registration
Statement, have been included and incorporated herein in reliance on the reports
of Coopers & Lybrand L.L.P., independent accountants, given on the authority of
that firm as experts in accounting and auditing.
 
                                       43

<PAGE>   46
 

<TABLE>
                         INDEX TO FINANCIAL STATEMENTS
 
<CAPTION>
                                                                                        PAGE
                                                                                        ----
<S>                                                                                     <C>
Report of Independent Accountants.....................................................  F-2
Balance Sheets as of September 30, 1994 and 1995......................................  F-3
Statements of Operations for the years ended September 30, 1993, 1994, and 1995.......  F-4
Statements of Stockholders' Equity for the years ended September 30, 1993, 1994, and
  1995................................................................................  F-5
Statements of Cash Flows for the years ended September 30, 1993, 1994, and 1995.......  F-6
Reconciliation of Net Income to Net Cash Provided by Operating Activities for the
  years ended September 30, 1993, 1994, and 1995......................................  F-7
Notes to Financial Statements.........................................................  F-8

</TABLE>

 
                                       F-1

<PAGE>   47
 

                       REPORT OF INDEPENDENT ACCOUNTANTS
 
To the Directors and Stockholders of Advanced Magnetics, Inc.:
 
     We have audited the accompanying balance sheets of Advanced Magnetics, Inc.
as of September 30, 1994 and 1995 and the related statements of operations,
stockholders' equity, and cash flows for each of the three years in the period
ended September 30, 1995. These financial statements are the responsibility of
the Company's management. Our responsibility is to express an opinion on these
financial statements based on our audits.
 
     We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
     In our opinion, the financial statements referred to above present fairly,
in all material respects, the financial position of Advanced Magnetics, Inc. as
of September 30, 1994 and 1995, and the results of its operations and its cash
flows for each of the three years in the period ended September 30, 1995, in
conformity with generally accepted accounting principles.
 
     As discussed in Note A to the financial statements, effective October 1,
1994, Advanced Magnetics, Inc. adopted the Statement of Financial Accounting
Standards No. 115, "Accounting for Certain Investments in Debt and Equity
Securities."
 
Boston, Massachusetts
November 8, 1995

 
                                       F-2

<PAGE>   48


<TABLE>
 
                            ADVANCED MAGNETICS, INC.
 
                                 BALANCE SHEETS
 
<CAPTION>
                                                                           SEPTEMBER 30,
                                                                    ---------------------------
                                                                       1994            1995
                                                                    -----------     -----------
<S>                                                                 <C>             <C>
ASSETS
Current Assets:
Cash and cash equivalents.........................................  $ 6,462,193     $ 1,066,419
Marketable securities (Note C)....................................   33,199,085      36,561,263
Accounts receivable...............................................      248,390       5,884,542
Recoverable income taxes (Note G).................................       90,117          90,117
Inventories (Note D)..............................................           --          55,567
Prepaid expenses..................................................      112,846          99,342
                                                                    -----------     -----------
          Total current assets....................................   40,112,631      43,757,250
                                                                    -----------     -----------
Property, plant and equipment:
Land..............................................................      360,000         360,000
Buildings.........................................................    4,316,706       4,320,766
Laboratory equipment..............................................    5,598,456       6,886,813
Furniture and fixtures............................................      324,453         516,418
                                                                    -----------     -----------
                                                                     10,599,615      12,083,997
Less -- accumulated depreciation and amortization.................    4,136,092       5,143,097
                                                                    -----------     -----------
Net property, plant and equipment.................................    6,463,523       6,940,900
                                                                    -----------     -----------
Other assets......................................................       96,546         145,072
                                                                    -----------     -----------
          Total assets............................................  $46,672,700     $50,843,222
                                                                    ===========     ===========
LIABILITIES AND STOCKHOLDERS' EQUITY
Current Liabilities:
Accounts payable..................................................  $   273,385     $   407,998
Accrued expenses (Note F).........................................      947,840       1,214,152
Income taxes payable (Note G).....................................           --         150,000
                                                                    -----------     -----------
          Total current liabilities...............................    1,221,225       1,772,150
                                                                    -----------     -----------
Commitments and Contingencies (Notes E, N and O)
Stockholders' equity (Notes C, H, I, K and L):
Preferred stock, par value $.01 per share, authorized 2,000,000
  shares; none issued.............................................           --              --
Common stock, par value $.01 per share, authorized 15,000,000
  shares; issued and outstanding 6,712,572 shares in 1994 and
  6,753,413 shares in 1995........................................       67,126          67,534
Additional paid-in capital........................................   44,660,834      45,093,972
Retained earnings.................................................      723,515       3,036,517
Net unrealized gain on marketable securities......................           --         873,049
                                                                    -----------     -----------
Total stockholders' equity........................................   45,451,475      49,071,072
                                                                    -----------     -----------
          Total liabilities and stockholders' equity..............  $46,672,700     $50,843,222
                                                                    ===========     ===========
</TABLE>

 
    The accompanying notes are an integral part of the financial statements.
 
                                       F-3

<PAGE>   49


<TABLE>
 
                            ADVANCED MAGNETICS, INC.
 
                            STATEMENTS OF OPERATIONS
 
<CAPTION>
                                                            FOR THE YEARS ENDED SEPTEMBER 30,
                                                        -----------------------------------------
                                                           1993            1994           1995
                                                        -----------     ----------     ----------
<S>                                                     <C>             <C>            <C>
Revenues:
License fees..........................................  $ 1,010,000     $5,505,000     $5,000,000
Royalties.............................................      906,138         15,924        189,493
Product sales.........................................    3,836,300        280,975      2,120,457
Contract research and development.....................      402,911             --             --
Interest, dividends and net gains and losses on sales
  of securities.......................................    2,823,102      1,845,005      2,287,311
                                                        -----------     ----------     ----------
          Total revenues..............................    8,978,451      7,646,904      9,597,261
Costs and Expenses:
Cost of product sales.................................    1,525,564         54,983        425,187
Contract research and development expenses............      193,391             --             --
Company-sponsored research and development expenses...    6,863,229      6,621,929      8,601,791
Charge (credit) for purchase of in-process research
  and development (Note O)............................           --        760,000       (380,000)
Selling, general and administrative expenses..........    2,777,840      1,963,480      1,759,348
                                                        -----------     ----------     ----------
          Total costs and expenses....................   11,360,024      9,400,392     10,406,326
Other income:
Gain on sale of in vitro product line (Note B)........           --      2,649,580      3,404,527
                                                        -----------     ----------     ----------
Income (loss) before provision for income taxes and
  cumulative effect of accounting change..............   (2,381,573)       896,092      2,595,462
Income tax provision..................................           --          8,000        400,000
                                                        -----------     ----------     ----------
Income (loss) before cumulative effect of accounting
  change..............................................   (2,381,573)       888,092      2,195,462
Cumulative effect of accounting change (Note C).......           --             --        117,540
                                                        -----------     ----------     ----------
Net income (loss).....................................  $(2,381,573)    $  888,092     $2,313,002
                                                        ===========     ==========     ==========
Net income (loss) per share before cumulative effect
  of accounting change................................  $     (0.36)    $     0.13     $     0.32
Cumulative effect of accounting change................           --             --           0.02
                                                        -----------     ----------     ----------
Income (loss) per share...............................  $     (0.36)    $     0.13     $     0.34
                                                        ===========     ==========     ==========
Weighted average number of common and common
  equivalent shares (Note A)..........................    6,651,061      6,806,525      6,870,839
</TABLE>

 
    The accompanying notes are an integral part of the financial statements.
 
                                       F-4

<PAGE>   50


<TABLE>
                            ADVANCED MAGNETICS, INC.
 
                       STATEMENTS OF STOCKHOLDERS' EQUITY
               FOR THE YEARS ENDED SEPTEMBER 30, 1993, 1994, 1995
 
<CAPTION>
                                                                                                   NET
                                                                                                UNREALIZED
                                                 COMMON STOCK       ADDITIONAL     RETAINED      GAIN ON        TOTAL
                                              -------------------     PAID-IN      EARNINGS     MARKETABLE   STOCKHOLDERS'
                                               SHARES     AMOUNT      CAPITAL      (DEFICIT)    SECURITIES      EQUITY
                                              ---------   -------   -----------   -----------   ----------   ------------
<S>                                           <C>         <C>       <C>           <C>            <C>          <C>
Balance at September 30, 1992...............  6,648,599   $66,486   $44,802,242   $ 2,216,996    $     --     $47,085,724
Shares issued in connection with the
  exercise of stock options.................     20,046       201        73,773            --          --          73,974
Shares surrendered in connection with the
  exercise of stock options.................     (3,481)      (35)      (43,708)           --          --         (43,743)
Shares issued in connection with employee
  stock purchase plan (Note H)..............     13,298       133       162,369            --          --         162,502
Common shares repurchased (Note K)..........    (18,000)     (180)     (242,276)           --          --        (242,456)
Net loss....................................         --        --            --    (2,381,573)         --      (2,381,573)
                                              ---------   -------   -----------   -----------    --------     -----------
Balance at September 30, 1993...............  6,660,462    66,605    44,752,400      (164,577)         --      44,654,428
Shares issued in connection with the
  exercise of stock options.................     70,648       706       417,406            --          --         418,112
Shares surrendered in connection with the
  exercise of stock options.................     (4,193)      (42)      (58,147)           --          --         (58,189)
Shares issued in connection with employee
  stock purchase plan (Note H)..............     10,355       104       105,517            --          --         105,621
Common shares repurchased (Note K)..........    (24,700)     (247)     (316,342)           --          --        (316,589)
Repurchase of warrants (Note K).............         --        --      (240,000)           --          --        (240,000)
Net profit..................................         --        --            --       888,092          --         888,092
                                              ---------   -------   -----------   -----------    --------     -----------
Balance at September 30, 1994...............  6,712,572    67,126    44,660,834       723,515          --      45,451,475
Shares issued in connection with the
  exercise of stock options.................     29,494       295       207,060            --          --         207,355
Shares surrendered in connection with the
  exercise of stock options.................     (1,476)      (15)      (24,588)           --          --         (24,603)
Shares issued in connection with employee
  stock purchase plan (Note H)..............     12,823       128       130,666            --          --         130,794
Repurchase of warrants (Note K).............         --        --       120,000            --          --         120,000
Net unrealized gain on marketable
  securities................................         --        --            --            --     873,049         873,049
Net profit..................................         --        --            --     2,313,002          --       2,313,002
                                              ---------   -------   -----------   -----------    --------     -----------
Balance at September 30, 1995...............  6,753,413   $67,534   $45,093,972   $ 3,036,517    $873,049     $49,071,072
                                              =========   =======   ===========   ===========    ========     ===========
</TABLE>

 
    The accompanying notes are an integral part of the financial statements.
 
                                       F-5

<PAGE>   51
 

<TABLE>
                            ADVANCED MAGNETICS, INC.
 
                            STATEMENTS OF CASH FLOWS
 
<CAPTION>
                                                          FOR THE YEARS ENDED SEPTEMBER 30,
                                                    ---------------------------------------------
                                                        1993             1994            1995
                                                    ------------     ------------     -----------
<S>                                                 <C>              <C>              <C>
Cash Flows from Operating Activities:
Cash received from customers......................  $  6,714,827     $  5,864,116     $ 5,380,513
Cash paid to suppliers and employees..............   (10,185,682)      (8,112,462)     (8,920,459)
Cash paid for purchase of in-process research and
  development (Note O)............................            --         (260,000)             --
Dividends and interest received...................     1,769,625        1,716,811       1,876,214
Income taxes paid.................................      (124,087)        (205,067)       (250,000)
Income tax refund.................................       212,136          622,849              --
Net realized gains on sales of marketable
  securities......................................     1,031,426          161,109          54,966
                                                    ------------     ------------     -----------
Net cash (used in) operating activities...........      (581,755)        (212,644)     (1,858,766)
                                                    ------------     ------------     -----------
Cash Flows from Investing Activities:
Proceeds from sales of marketable securities......    24,725,632        6,863,154       1,385,830
Proceeds from notes and bonds maturing............       150,000               --       3,000,000
Purchase of marketable securities.................   (27,105,583)     (25,117,742)     (6,703,475)
Capital expenditures..............................    (2,304,771)        (780,586)     (1,484,382)
(Increase) decrease in other assets and
  deposits........................................       200,447          (36,853)        (48,526)
                                                    ------------     ------------     -----------
Net cash (used in) investing activities...........    (4,334,275)     (19,072,027)     (3,850,553)
                                                    ------------     ------------     -----------
Cash Flows from Financing Activities:
Proceeds from issuance of common stock............       192,733          465,544         313,545
Purchase of treasury stock........................      (242,456)        (316,589)             --
Purchase of warrants..............................            --         (240,000)             --
                                                    ------------     ------------     -----------
Net cash provided by (used in) financing
  activities......................................       (49,723)         (91,045)        313,545
                                                    ------------     ------------     -----------
Net (decrease) in cash and cash equivalents.......    (4,965,753)     (19,375,716)     (5,395,774)
Cash and cash equivalents at beginning of year....    30,803,662       25,837,909       6,462,193
                                                    ------------     ------------     -----------
Cash and cash equivalents at end of year..........  $ 25,837,909     $  6,462,193     $ 1,066,419
                                                    ============     ============     ===========
</TABLE>

 
    The accompanying notes are an integral part of the financial statements.
 
                                       F-6

<PAGE>   52


<TABLE>
                            ADVANCED MAGNETICS, INC.
 
                          RECONCILIATION OF NET INCOME
                  TO NET CASH PROVIDED BY OPERATING ACTIVITIES
 
<CAPTION>
                                                           FOR THE YEARS ENDED SEPTEMBER 30,
                                                      -------------------------------------------
                                                         1993            1994            1995
                                                      -----------     -----------     -----------
<S>                                                   <C>             <C>             <C>
Net income (loss)...................................  $(2,381,573)    $   888,092     $ 2,313,002
                                                      -----------     -----------     -----------
Adjustments to Reconcile Net Income to Net Cash Used
  in Operating Activities, net of assets disposed
  of:
Depreciation and amortization.......................      821,246         877,803       1,007,005
Decrease in deferred income tax asset...............      349,948              --              --
Net unrealized loss on market value of securities...           --         117,540              --
Cumulative effect of accounting change..............           --              --        (117,540)
Accretion of U.S. Treasury Notes discount...........           --              --         (53,943)
(Increase) decrease in accounts receivable..........      537,427         (22,332)     (2,231,625)
(Increase) decrease in inventories..................      155,125              --         (55,567)
(Increase) decrease in prepaid expenses.............     (149,088)        134,063          13,504
(Increase) decrease in recoverable income taxes.....      (95,948)        259,831              --
(Decrease) increase in accounts payable and accrued
  expenses..........................................      181,108        (318,061)        900,925
Increase in income taxes payable....................           --              --         150,000
Gain on sale of in vitro product line (Note B)......           --      (2,649,580)     (3,404,527)
Accrual (credit) for the purchase of in-process
  research and development (Note O).................           --         500,000        (380,000)
                                                      -----------     -----------     -----------
          Total adjustments.........................    1,799,818      (1,100,736)     (4,171,768)
                                                      -----------     -----------     -----------
Net cash provided by (used in) operating
  activities........................................  $  (581,755)    $  (212,644)    $(1,858,766)
                                                      ===========     ===========     ===========
</TABLE>

 
    The accompanying notes are an integral part of the financial statements.
 
                                       F-7

<PAGE>   53
 
                            ADVANCED MAGNETICS, INC.
 
                         NOTES TO FINANCIAL STATEMENTS
 
A. SUMMARY OF ACCOUNTING POLICIES:
 
  Business
 
     Founded in November 1981, Advanced Magnetics Inc., a Delaware Corporation
(the "Company"), is a biopharmaceutical company engaged in the development and
manufacture of compounds utilizing the Company's core proprietary colloidal
superparamagnetic particle technology for magnetic resonance imaging ("MRI") and
for polysaccharide directed, receptor-mediated drug delivery systems. The
initial products developed by the Company are diagnostic imaging agents for use
in conjunction with MRI to aid in the diagnosis of cancer and other diseases. In
therapeutics, the Company is developing antiviral products, for the treatment of
Hepatitis.
 
  Cash and Cash Equivalents
 
     Cash and cash equivalents consist of cash on hand, money market funds and
marketable securities having a maturity of less than three months at the date
acquired. Approximately 55% of the cash and cash equivalents are held in two
money-market accounts.
 
  Marketable Securities
 
     In its first fiscal quarter ended December 31, 1994, the Company adopted
Statement of Financial Accounting Standards No. 115, "Accounting for Certain
Investments in Debt and Equity Securities." Prior period financial statements
have not been restated. The Company's current portfolio consists of securities
classified as available-for-sale which are recorded at fair market value. The
fair values of marketable securities are based on quoted market prices. Net
unrealized gains or losses on marketable securities are recorded as a separate
component of equity. Interest income is accrued as earned. Dividend income is
accrued on the ex-dividend date, and net realized gains and losses are computed
on the basis of average cost and are recognized when realized.
 
  Inventories
 
     Inventories are stated at the lower of cost (determined on a first-in,
first-out basis) or market.
 
  Property, Plant and Equipment
 
     Property, plant and equipment are stated at cost. The cost of additions and
improvements is charged to the property accounts while maintenance and repairs
are expenses as incurred. Upon sale or other disposition of property and
equipment, the cost and related depreciation are removed from the accounts and
any resulting gain or loss is reflected in income.
 
  Depreciation and Amortization
 
     Depreciation and amortization are recorded on the straight line method
based on rates sufficient to provide for retirement over estimated useful lives
as follows: buildings -- 40 years; laboratory equipment and furniture and
fixtures -- 5 years; and leasehold improvements -- over the life of the lease.
 
  Revenue Recognition
 
     Revenue is recognized when products are shipped, when contract objectives
are achieved or when research activities are performed. License and royalty
revenues are accrued as earned.
 
                                       F-8

<PAGE>   54
 
                            ADVANCED MAGNETICS, INC.
 
                  NOTES TO FINANCIAL STATEMENTS -- (CONTINUED)
 
  Income Taxes
 
     The provision for income taxes includes federal and state income taxes
currently payable and deferred income taxes arising from the recognition of
certain income and expenses in different periods for financial and tax reporting
purposes.
 
  Income (Loss) per Share
 
     Income per share is computed on the basis of the weighted average number of
common and common share equivalents outstanding during each period. Loss per
share is computed on the weighted average number of shares outstanding during
the period.
 
B. SALE OF IN VITRO PRODUCT LINE:
 
     On October 15, 1993, the Company sold its in vitro product line to
PerSeptive Biosystems, Inc. ("PerSeptive") for 151,759 shares of PerSeptive
common stock which was worth $4,156,674 as of that date, plus an additional
earn-out amount based on the results of fiscal 1995. The earn-out included a
percentage of PerSeptive's royalty derived from the in vitro product line for
the fiscal year ended September 30, 1995 as well as a percentage of 1993 product
line sales. The Company recognized pre-tax gains on this sale of $3,404,527 and
$2,649,580 in fiscal 1995 and 1994, respectively. PerSeptive has elected to
satisfy the 1995 earn-out amount with shares of PerSeptive common stock of
equivalent value. The number of shares to be issued for the earn-out will be
determined when PerSeptive files a registration statement for these shares with
the Securities and Exchange Commission. PerSeptive is required to file this
statement no later than September 30, 1996, and interest will accrue if payment
is received after December 15, 1995. The in vitro product line generated
revenues of $5,017,000 and pre-tax income of $1,635,000 for the fiscal year
ended September 30, 1993. Net assets included in the sale of the in vitro
product line were $1,592,000 at October 15, 1993. This amount consisted of
current assets and property and equipment, net of current liabilities.
 
C. MARKETABLE SECURITIES:
 

<TABLE>
     The cost and fair value of the marketable securities portfolio at September
30, 1995 are as follows:
 
<CAPTION>
                                                                   COST         FAIR VALUE
                                                                -----------     -----------
    <S>                                                         <C>             <C>
    U.S. government securities
      Due in one year or less.................................  $ 9,501,365     $ 9,476,430
      Due after one through five years........................   14,869,406      14,737,500
    Corporate debt
      Due after five through ten years........................    1,980,040       2,002,500
    Preferred stock...........................................    6,116,668       5,740,023
    Common stock..............................................    3,220,735       4,604,810
                                                                -----------     -----------
                                                                $35,688,214     $36,561,263
                                                                ===========     ===========
</TABLE>

 
     At September 30, 1994, the aggregate cost and fair value of the marketable
securities portfolio were $33,316,625 and $33,199,085, respectively.
 
     At September 30, 1995, gross unrealized holding gains and gross unrealized
holding losses were $1,722,965 and $849,916, respectively, resulting in a net
unrealized holding gain of $873,049 which was recorded as a separate component
of equity. At September 30, 1994, the Company recorded a $117,540 unrealized net
loss on the fair value of securities. In the first fiscal quarter ended December
31, 1994, the Company recorded a cumulative effect of the accounting change of
$117,540 including the reversal of the reserve for the carrying value of the
marketable securities.
 
                                       F-9

<PAGE>   55
 
                            ADVANCED MAGNETICS, INC.
 
                  NOTES TO FINANCIAL STATEMENTS -- (CONTINUED)
 
     During the year ended September 30, 1995, gross realized gains and gross
realized losses on the sale of marketable securities were $57,394 and $2,428,
respectively, resulting in a net realized gain of $54,966. Proceeds relating to
the gross realized gains and gross realized losses were $693,224 and $747,572,
respectively. Proceeds from U.S. treasury bonds maturing were $3,000,000.
 

<TABLE>
     Interest, dividends and net gains (losses) on sales of securities consist
of the following:
 
<CAPTION>
                                                            YEARS ENDED SEPTEMBER 30,
                                                     ----------------------------------------
                                                        1993           1994           1995
                                                     ----------     ----------     ----------
    <S>                                              <C>            <C>            <C>
    Interest income................................  $1,259,960     $1,135,614     $1,644,329
    Dividend income................................     531,716        665,822        588,016
    Net gains on sales of securities...............   1,031,426        161,109         54,966
    Unrealized loss included in the determination
      of income....................................          --       (117,540)            --
                                                     ----------     ----------     ----------
                                                     $2,823,102     $1,845,005     $2,287,311
                                                     ==========     ==========     ==========
</TABLE>

 
D. INVENTORIES:
 
     At September 30, 1994, there were no inventories as the Company's products
were predominately in the research and development stages and the Company
produced products for sale on a made-to-order basis only. In the fourth fiscal
quarter ended September 30, 1995, the Company began to accumulate production
costs for its products for future sale resulting in an ending inventory of
$55,567 of raw materials.
 
E. COMMITMENTS:
 
     The Company leases laboratory, office and warehouse space under various
agreements. Rental expenses for the years ended September 30, 1993, 1994, and
1995 amounted to $237,755, $38,017, and $320,920, respectively. Future minimum
lease payments for fiscal 1996, 1997 and 1998 amount to $336,368, $216,331 and
$35,233, respectively.
 
F. ACCRUED EXPENSES:
 

<TABLE>
     Accrued expenses consist of the following at September 30:
 
<CAPTION>
                                                                     1994          1995
                                                                   ---------    -----------
    <S>                                                             <C>          <C>
    Salaries and other compensation..............................   $190,497     $  194,881
    Professional fees............................................    119,925        154,668
    Other........................................................    137,418        348,856
    Accrual for payment due Bristol-Myers Squibb Co. for purchase
      of in-process research and development.....................    500,000             --
    Payable for the purchase of marketable securities............         --        515,747
                                                                    --------     ----------
                                                                    $947,840     $1,214,152
                                                                    ========     ==========
</TABLE>

 
G. INCOME TAXES:
 
     Deferred tax assets and deferred tax liabilities are recognized based on
temporary differences between the financial reporting and tax basis of assets
and liabilities using statutory rates. A valuation allowance is recorded against
deferred tax assets if it is more likely than not that some or all of the
deferred tax assets will not be realized.
 
                                      F-10

<PAGE>   56
 
                            ADVANCED MAGNETICS, INC.
 
                  NOTES TO FINANCIAL STATEMENTS -- (CONTINUED)
 

<TABLE>
     The income tax provision consists of the following:
 
<CAPTION>
                                                              YEARS ENDED SEPTEMBER 30,
                                                          ---------------------------------
                                                            1993         1994        1995
                                                          ---------     ------     --------
    <S>                                                   <C>           <C>        <C>
    Currently payable:
      Federal...........................................  $(349,948)    $   --     $385,000
      State.............................................         --      8,000       15,000
                                                          ---------     ------     --------
                                                           (349,948)     8,000      400,000
                                                          ---------     ------     --------
    Deferred:
      Federal...........................................    349,948         --           --
      State.............................................         --         --           --
                                                          ---------     ------     --------
                                                            349,948         --           --
                                                          ---------     ------     --------
                                                          $      --     $8,000     $400,000
                                                          =========     ======     ========
</TABLE>

 

<TABLE>
     The provisions for income taxes were at different rates than the U.S.
statutory rates for the following reasons:
 
<CAPTION>
                                                                YEARS ENDED SEPTEMBER 30,
                                                              -----------------------------
                                                              1993        1994        1995
                                                              -----       -----       -----
    <S>                                                       <C>         <C>         <C>
    U.S. Federal statutory tax (benefit) rate...............  (34.0)%      34.0%       34.0%
    Dividends received deductions...........................   (5.3)      (17.7)       (5.2)
    Other, including a prior year tax adjustment............    1.6         1.7         1.0
    Losses without tax benefit..............................   37.7          --          --
    Tax benefit of temporary differences....................     --       (17.1)      (14.4)
                                                              -----       -----       -----
                                                                 --%        0.9%       15.4%
                                                              =====       =====       =====
</TABLE>

 

<TABLE>
     The components of the deferred tax assets and liabilities at September 30,
were as follows:
 
<CAPTION>
                                                                   1994            1995
                                                                -----------     -----------
    <S>                                                         <C>             <C>
    Assets
      Net operating loss carryforwards........................  $   847,811     $   460,506
      Research and experimentation tax credit carryforward....    1,331,147       1,656,069
      Deductible intangibles..................................    1,492,948         911,066
      Other...................................................      224,697         630,670
    Liabilities
      Property, plant and equipment depreciation..............     (646,623)       (249,373)
      Other...................................................      (63,199)        (96,598)
                                                                -----------     -----------
                                                                  3,186,781       3,312,340
    Valuation allowance.......................................   (3,186,781)     (3,312,340)
                                                                -----------     -----------
    Net deferred taxes........................................  $        --     $        --
                                                                ===========     ===========
</TABLE>

 
     Due to the uncertainty surrounding the realization of the favorable tax
attributes in future tax returns, the Company has placed a valuation allowance
against its otherwise recognizable net deferred tax assets. Realization of
favorable tax attributes is, therefore, reflected as a tax benefit in the
provision for income taxes.
 
                                      F-11

<PAGE>   57
 
                            ADVANCED MAGNETICS, INC.
 
                  NOTES TO FINANCIAL STATEMENTS -- (CONTINUED)
 

<TABLE>
     The net tax effects of temporary differences on the provision for income
taxes were as follows:
 
<CAPTION>
                                                             YEARS ENDED SEPTEMBER 30,
                                                         ----------------------------------
                                                           1993         1994         1995
                                                         --------     --------     --------
    <S>                                                  <C>          <C>          <C>
    Tax benefit of temporary differences for financial
      reporting purposes...............................  $     --     $407,787     $220,831
    Tax benefit of net operating loss for income tax
      purposes.........................................   349,948           --           --
                                                         --------     --------     --------
                                                         $349,948     $407,787     $220,831
                                                         ========     ========     ========
</TABLE>

 
     At September 30, 1995, the recoverable income taxes result from carryback
of losses for federal income tax purposes to amounts paid for income taxes in
prior years.
 
     At September 30, 1995, the Company had unused net operating loss (NOL)
carryforwards for federal income tax purposes of approximately $830,000 which
expire in fiscal 2010. The Company also has federal research and experimentation
credits of approximately $1,500,000 which expire in fiscal 2010.
 
H. EMPLOYEE STOCK PURCHASE PLAN:
 
     The Company's 1992 Employee Stock Purchase Plan (the "Purchase Plan")
provides for the issuance of up to 150,000 shares of common stock to employees
of the Company. Under the terms of the Purchase Plan, eligible employees may
purchase shares in five annual offerings ending 1997, through payroll deductions
of up to a maximum of 10% of the employee's earnings, at a price equal to the
lower of 85% of the fair market value of the stock on the applicable annual
offering commencement date of June 1 or termination date of May 31. The third
offering under the Purchase Plan ended on May 31, 1995 and 12,823 shares of
common stock were purchased by eligible employees at a price of approximately
$10.20 per share. As of September 30, 1995, 36,476 shares have been issued under
the Purchase Plan.
 
I. STOCK OPTION PLAN:
 
     The Company's 1993 Stock Option Plan (the "1993 Stock Plan") provides for
the grant of options to the Company's directors, officers, employees and
consultants to purchase up to an aggregate of 500,000 shares of common stock at
a price equal to the fair market value of the stock at the date of grant. The
maximum term of the options under the 1993 Stock Plan is ten years. The number
of shares available for future grants at September 30, 1995 was 289,800.
 
     The Company's 1983 Stock Option Plan (the "Plan") does not allow for option
grants after June 1993. The Plan provided for the grant of options to purchase
up to 900,000 shares of common stock at a price equal to the fair market value
of the stock at the date of grant to the Company's employees and mandatory
grants to outside directors upon initial election to the Board of Directors. The
maximum terms of incentive stock options and non-statutory options under the
Plan are ten years and ten years plus thirty days, respectively.
 
     The Company has also granted to certain scientific advisors nonstatutory
options to purchase a total of 29,625 shares of common stock at a price equal to
fair market value at the date of grant. All options have been exercised.
 
                                      F-12

<PAGE>   58
 
                            ADVANCED MAGNETICS, INC.
 
                  NOTES TO FINANCIAL STATEMENTS -- (CONTINUED)
 

<TABLE>
     The table below summarizes stock option activity during the past three
fiscal years for the Company's 1993 and 1983 Stock Option Plans:
 
<CAPTION>
                                                                NUMBER
                                                               OF SHARES       OPTION PRICE
                                                               ---------     ----------------
    <S>                                                        <C>           <C>
    Options outstanding at September 30, 1992................   282,032      $ 1.33 to $11.88
      Granted................................................    35,100       13.00 to  15.00
      Exercised..............................................   (20,046)       1.00 to  11.00
      Expired................................................    (4,927)       7.00 to  15.00
                                                                -------
    Options outstanding at September 30, 1993................   292,159        1.00 to  15.00
      Granted................................................   126,500       12.00 to  16.00
      Exercised..............................................   (70,648)       1.00 to  12.00
      Expired................................................   (40,752)       7.00 to  15.00
                                                                -------
    Options outstanding at September 30, 1994................   307,259        1.00 to  16.00
      Granted................................................    86,200       15.00 to  22.00
      Exercised..............................................   (29,494)       1.00 to  15.00
      Expired................................................    (4,775)      12.00 to  15.00
                                                                -------
    Options outstanding at September 30, 1995
      (177,140 shares exercisable)...........................   359,190        1.33 to  22.00
</TABLE>

 
     On November 5, 1991, the Company's Board of Directors adopted the 1992
Non-Employee Director Stock Option Plan which the Stockholders approved. This
plan provides for the grant to each non-employee director on November 5, 1991,
and each fifth anniversary thereafter, an option to purchase 5,000 shares of
common stock up to an aggregate of 100,000 shares at a price equal to the fair
market value of the stock at the date of the grant, vesting over a five year
period. Under this plan, options to purchase 30,000 shares of common stock at a
price of $21.00 per share were granted, none of which have been exercised. No
grants may be made under this plan after November 4, 2001.
 
     On November 10, 1992, the Company's Board of Directors adopted the 1993
Non-Employee Director Stock Option Plan which the Stockholders approved. This
plan provides for the grant to each non-employee director on November 10, 1992,
and each sixth anniversary thereafter, an option to purchase 5,000 shares of
common stock up to an aggregate of 100,000 shares at a price equal to the fair
market value of the stock at the date of the grant, vesting over a five year
period. Under this plan, options to purchase 30,000 shares of common stock at a
price of $14.50 per share were granted, none of which have been exercised. No
grants may be made under this plan after November 10, 2002.
 
J. EMPLOYEE'S SAVING PLAN:
 
     The Company provides a 401(k) Plan to employees of the Company by which
they may defer compensation for income tax purposes under Section 401(k) of the
Internal Revenue Code. Each employee may elect to defer a percentage of his or
her salary on a pre-tax basis up to a specified maximum percentage. The Company
matches every dollar each employee contributes to the 401(k) Plan up to six
percent of each employee's salary to a maximum of $2,000 annually per employee.
Salary deferred by employees and contributions by the Company to the 401(k) Plan
are not taxable to employees until withdrawn from the 401(k) Plan and
contributions are deductible by the Company when made. The amount of the
Company's matching contribution for the 401(k) Plan was $114,789, $79,851, and
$99,751 for 1993, 1994 and 1995, respectively.
 
                                      F-13

<PAGE>   59
 
                            ADVANCED MAGNETICS, INC.
 
                  NOTES TO FINANCIAL STATEMENTS -- (CONTINUED)
 
K. COMMON STOCK TRANSACTIONS:
 
     On February 11, 1991, Squibb Diagnostics, a division of Bristol-Myers
Squibb Co., purchased for $950,000 a warrant covering 600,000 shares of common
stock exercisable at $10.92 per share and escalating in exercise price in
subsequent years. On August 30, 1994, the Company signed an agreement to
reacquire the development and marketing rights to the MRI contrast agent
Combidex. As part of the transaction, Bristol-Myers Squibb Co. returned the
warrant which was valued at $240,000 to the Company. In the first quarter of
fiscal 1995, the Company and Bristol-Myers Squibb Co. agreed to modify the
agreement. As a result, payments to be made under the agreement were modified
(See Note O). Accordingly, the Company adjusted the value of the warrant to
purchase 600,000 shares of the Company's common stock by $120,000 in the first
quarter of fiscal 1995.
 
     In November 1993, the Board of Directors authorized the purchase of 350,000
shares of the Company's common stock on the open market. Through September 30,
1995, the Company purchased 24,700 shares for $316,589 and the shares have been
retired. The Board had previously authorized the purchase of 500,000 shares of
which 170,100 were retired through fiscal 1993.
 
L. PREFERRED STOCK:
 
     The preferred stock may be issued from time to time in one or more series.
The rights, preferences, restrictions, qualifications and limitations of such
stock shall be determined by the Board of Directors.
 
M. BUSINESS SEGMENTS AND CUSTOMERS:
 
     The Company's operations are located solely within the United States. The
Company is focused principally on developing and manufacturing MRI contrast
agents and therapeutic drug delivery systems. Prior to fiscal 1994, the Company
was also engaged in developing, producing and marketing in vitro medical
diagnostic products for research and clinical laboratories, hospitals, and other
manufacturers of diagnostics products. Accordingly, its revenues are
attributable to one principal business segment. The Company performs ongoing
credit evaluations of its customers and generally does not require collateral.
Two customers accounted for 52% and 23% respectively of the Company's revenues
in fiscal 1995. Two customers accounted for 39% and 33% respectively of the
Company's revenues in fiscal 1994 and three customers accounted for 11%, 9% and
5% respectively of the Company's revenues in fiscal 1993.
 
     Revenues in fiscal 1993, 1994 and 1995 from customers and licensees outside
of the United States, principally in Europe and Japan, amounted to 16%, 3% and
23%, respectively.
 
N. LEGAL PROCEEDINGS:
 
     The Company and certain of its officers were sued in an action in the
United States District Court for the District of Massachusetts on September 3,
1992. The plaintiff, a former consultant to the Company, claims that he was
incorrectly omitted as an inventor or joint inventor on certain of the Company's
patents and on pending applications, and seeks injunctive relief and unspecified
monetary damages. In April 1993, the plaintiff's federal court claims were
dismissed, and the plaintiff appealed. The Appeals Court vacated the judgment
and remanded the case to the U.S. District Court. The plaintiff filed a related
case in the Superior Court of the Commonwealth of Massachusetts. The Superior
Court has dismissed most of the related tort claims on summary judgment. While
the final outcome of these actions cannot be determined, the Company believes
that the plaintiff's claims are without merit and intends to defend the actions
vigorously. There can be no assurance, however, that the Company will be able to
successfully defend this action and the failure by the Company to prevail for
any reason could have an adverse effect on the Company's future business,
financial condition and results of operations.
 
O. AGREEMENTS:
 
     In fiscal 1993, the Company entered into an agreement with Sterling
Winthrop, Inc. ("Sterling") for a product license and exclusive marketing rights
to Advanced Magnetics' Feridex I.V. MRI liver imaging
 
                                      F-14

<PAGE>   60
 
                            ADVANCED MAGNETICS, INC.
 
                  NOTES TO FINANCIAL STATEMENTS -- (CONTINUED)
 
contrast agent in the United States, Canada, Mexico and Australia. Under the
agreement, Sterling would have paid up to $7,750,000 in license fees based on
achieving certain milestones, of which $1,000,000 was received and recognized in
license revenues in fiscal 1993.
 
     In fiscal 1994, Sterling paid a $2,500,000 non-refundable milestone payment
for the Company's filing of a New Drug Application ("NDA") with the U.S. Food
and Drug Administration ("FDA") for Feridex I.V. On October 6, 1994, the Company
terminated its marketing and distribution agreement with Sterling as a direct
result of the sale by Sterling of its prescription pharmaceutical business. The
agreement with Sterling was not assignable without the Company's consent, which
was not sought by Sterling nor given by the Company.
 
     In fiscal 1991, the Company entered into agreements with Squibb Diagnostics
granting exclusive worldwide rights (except for Japan, Western Europe and
Brazil) to manufacture and sell two MRI products, AMI-HS and Combidex. In
addition, Squibb Diagnostics received the right to use the Company's core
technology in its own development of other MRI contrast agents. The Company was
to receive up to $10,000,000 in licensing fees, of which $4,000,000 was received
and recognized in license revenues when the agreements were signed in fiscal
1991 and $1,000,000 was received in fiscal 1992 when the Company filed an
Investigational New Drug ("IND") exemption with the FDA for Combidex.
 
     The Company and Squibb Diagnostics amended their agreement regarding
Combidex in fiscal 1994 for which the Company received a non-refundable license
fee of $1,000,000. Also in fiscal 1994, the Company and Squibb Diagnostics
terminated their agreement with respect to the AMI-HS product and Squibb
Diagnostics paid a $2,000,000 license fee milestone payment for Combidex. On
August 30, 1994, the Company signed an agreement to reacquire the development
and marketing rights to Combidex previously licensed to Squibb Diagnostics. The
Company agreed to pay Bristol-Myers Squibb Co. $1,000,000 in two cash payments,
of which $500,000 was paid on August 30, 1994 and $500,000 was to be paid upon
acceptance of Combidex product suitable for use in worldwide preclinical and
clinical studies. Furthermore, the Company is required to pay up to $2,750,000
in future royalties based on the Company's sale of Combidex. As part of the
transaction, Bristol-Myers Squibb Co. returned to the Company a warrant to
purchase 600,000 shares of the Company's Common Stock, valued at $240,000. The
Company recorded a $760,000 expense which represented the value of in-process
research and development reacquired. In the first quarter of fiscal 1995, the
Company and Bristol-Myers Squibb Co. agreed that the 1,200 vials of Combidex
delivered to the Company were not acceptable. In addition, they modified their
prior agreement whereby Bristol-Myers Squibb Co. was relieved of its obligation
to deliver Combidex to the Company for clinical trials and the Company was
relieved of its obligation to pay $500,000 to Bristol-Myers Squibb Co.
Accordingly, the Company recorded a credit for $380,000 to the purchase of
in-process research and development and adjusted the value of the warrant
downward by $120,000 in the first quarter of fiscal 1995.
 
     On February 1, 1995, the Company entered into an agreement with Berlex
Laboratories, Inc. ("Berlex") granting Berlex a product license and exclusive
marketing rights to Feridex I.V. in the United States and Canada. Under the
terms of the agreement, Berlex paid a $5,000,000 non-refundable license fee and
will pay an additional $5,000,000 license fee when the product has been approved
for commercial marketing in the United States by the FDA. In addition, the
Company will receive payments for manufacturing the product and royalties on
future sales. The Company submitted an NDA for Feridex I.V. to the FDA in
February 1994.
 
     On May 9, 1995, the Company entered into a Research and License Agreement
with the General Hospital Corporation, a not-for-profit Massachusetts
Corporation doing business as Massachusetts General Hospital ("MGH"). The
agreement covers organ-specific, receptor-directed, ultrasmall superparamagnetic
iron oxide for use as MRI contrast agents. The target organ for the initial
collaboration is the pancreas. Under the agreement, the Company agreed to pay
MGH $300,000, of which $150,000 was paid in fiscal year ended December 31, 1995,
with the remainder to be paid in fiscal 1996. However, payments could exceed
this amount depending on milestone achievements and product sales.
 
                                      F-15

<PAGE>   61
 
                            ADVANCED MAGNETICS, INC.
 
                  NOTES TO FINANCIAL STATEMENTS -- (CONTINUED)
 
P. RELATED PARTY TRANSACTIONS:
 
     During the fiscal years ended September 30, 1993, 1994, and 1995, the
Company paid approximately $52,000, $19,650 and $7,050, respectively, to
Fahnestock & Co. Inc. as commissions in transactions involving its investments
in securities. Mr. Leslie Goldstein, a Stockholder and member of the Company's
Board of Directors and the brother of Jerome Goldstein, Chairman of the Board,
President and Treasurer of the Company, is employed by SRG Associates, a
division of Fahnestock & Co. Inc., as an investment analyst and advisor.


<TABLE>
Q. QUARTERLY FINANCIAL DATA -- UNAUDITED:
 
     The following table provides quarterly data for the fiscal years ended
September 30, 1994 and 1995.
 
<CAPTION>
                                                            FISCAL 1995 QUARTERS ENDED
                                            ----------------------------------------------------------
                                            DEC. 31, 1994     MARCH 31       JUNE 30      SEPTEMBER 30
                                            -------------    ----------    -----------    ------------
<S>                                           <C>            <C>           <C>              <C>
License fees..............................    $       --     $5,000,000    $        --      $       --
Royalties.................................            --             --         38,366         151,127
Product sales.............................        55,259        789,026      1,276,172              --
Interests, dividends and net gains and
  losses on sales of securities...........       681,986        438,669        575,172         591,484
                                              ----------     ----------    -----------      ----------
          Total revenues..................       737,245      6,227,695      1,889,710         742,611
Cost of product sales.....................        11,050        157,804        256,333              --
Operating expenses........................     1,533,737      2,440,599      3,090,004       2,916,799
Gain on sale of in vitro product line
  (Note B)................................            --             --             --       3,404,527
Net income (loss) before cumulative 
  effect of accounting change.............      (807,542)     3,254,292     (1,278,127)      1,026,839
Cumulative effect of account change
  (Note C)................................       117,540
Net income (loss).........................    $ (690,002)    $3,254,292    $(1,278,127)     $1,026,839
Net income (loss) per share before
  cumulative effect of account change.....    $    (0.12)    $     0.48    $     (0.19)     $     0.15
Cumulative effect of account change.......           .02             --             --              --
                                              ----------     ----------    -----------      ----------
Income (loss) per share...................    $    (0.10)    $     0.48    $     (0.19)     $     0.15
</TABLE>

 

<TABLE>
<CAPTION>
                                                            FISCAL 1994 QUARTERS ENDED
                                            ----------------------------------------------------------
                                            DEC. 31, 1993     MARCH 31       JUNE 30      SEPTEMBER 30
                                            -------------    ----------    -----------    ------------
<S>                                           <C>            <C>            <C>            <C>
License fees..............................    $1,005,000     $2,000,000     $2,500,000     $        --
Royalties.................................        13,461             --             --           2,463
Product sales.............................        61,600        138,950         25,665          54,760
Interest, dividends and net gains and
  losses on sales of securities...........       409,167        476,985        535,896         422,957
                                              ----------     ----------     ----------     -----------
          Total revenues..................     1,489,228      2,615,935      3,061,561         480,180
Cost of product sales.....................        12,300         26,600          5,133          10,950
Operating expenses........................     2,092,298      2,201,177      2,247,376       2,804,558
Gain on sale of in vitro product line
  (Note B)................................     2,649,580             --             --              --
Net income (loss).........................    $1,948,710     $  371,658     $  905,552     $(2,337,828)
Net income (loss) per share...............    $     0.28     $     0.05     $     0.13     $     (0.35)
</TABLE>

 
                                      F-16

<PAGE>   62
 
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
 
     NO PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATIONS IN CONNECTION WITH THIS OFFERING OTHER THAN THOSE CONTAINED IN
THIS PROSPECTUS AND, IF GIVEN OR MADE, SUCH OTHER INFORMATION AND
REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING BEEN AUTHORIZED BY THE COMPANY
OR THE UNDERWRITERS. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY SALE MADE
HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES, CREATE ANY IMPLICATION THAT THERE HAS
BEEN NO CHANGE IN THE AFFAIRS OF THE COMPANY SINCE THE DATE HEREOF OR THAT THE
INFORMATION CONTAINED HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO ITS DATE.
THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL OR A SOLICITATION OF AN
OFFER TO BUY ANY SECURITIES OTHER THAN THE REGISTERED SECURITIES TO WHICH IT
RELATES. THIS PROSPECTUS DOES NOT CONSTITUTE AN OFFER TO SELL OR A SOLICITATION
TO BUY SUCH SECURITIES IN ANY CIRCUMSTANCES IN WHICH SUCH OFFER OR SOLICITATION
IS UNLAWFUL.
 
                            ------------------------
 
 
                              TABLE OF CONTENTS
 

<TABLE>
<CAPTION>
                                             PAGE
                                             ----
<S>                                          <C>
Available Information......................    2
Incorporation of Certain Documents by
  Reference................................    2
Prospectus Summary.........................    3
The Company................................    3
Risk Factors...............................    6
Use of Proceeds............................   12
Price Range of Common Stock and Dividend
  Policy...................................   13
Capitalization.............................   14
Selected Financial Data....................   15
Management's Discussion and Analysis of
  Financial Condition and Results of
  Operations...............................   17
Business...................................   22
Management.................................   37
Principal and Selling Stockholders.........   39
Description of Capital Stock...............   41
Underwriting...............................   42
Legal Matters..............................   43
Experts....................................   43
Index to Financial Statements..............  F-1
</TABLE>

 
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
                                1,350,000 SHARES
 
                                [INSERT GRAPHIC]
 
                            ADVANCED MAGNETICS, INC.
 
                                  COMMON STOCK
                            ------------------------
 
                                   PROSPECTUS
                            ------------------------
                            PAINEWEBBER INCORPORATED
 
                          DONALDSON, LUFKIN & JENRETTE
                             SECURITIES CORPORATION
                             OPPENHEIMER & CO., INC.
                                 TUCKER ANTHONY
                                  INCORPORATED
                            ------------------------
 
                               MARCH      , 1996
 
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------

<PAGE>   63
 

                                   PART II
 
              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
 
ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.


<TABLE>
 
        Estimated expenses (other than underwriting discounts and commissions)
payable in connection with the sale of the Common Stock offered hereby are as
follows:

    <S>                                                               <C>
    Registration Fee..............................................    $ 12,715
    American Stock Exchange Additional Listing Fee................       1,000
    NASD Filing Fee...............................................       4,188
    Printing and Engraving Expenses...............................      80,000
    Legal Fees and Expenses.......................................     175,000
    Accounting Fees and Expenses..................................      75,000
    Blue Sky Fees and Expenses (including legal fees).............      15,000
    Miscellaneous.................................................      87,097
                                                                      --------
              Total...............................................    $450,000
                                                                      ========
</TABLE>

 
ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
        Section 145 of the General Corporation Law of Delaware empowers a
corporation to indemnify any person who was or is a party or is threatened to be
made a party to any threatened, pending or completed action, suit or proceeding,
whether civil, criminal, administrative or investigative, by reason of the fact
that he or she is or was a director, officer, employee or agent of the
corporation or another enterprise if serving at the request of the corporation.
Depending on the character of the proceeding, a corporation may indemnify
against expenses (including attorney's fees), judgments, fines and amounts paid
in settlement actually and reasonably incurred in connection with such action,
suit or proceeding if the person indemnified acted in good faith and in a manner
he or she reasonably believed to be in or not opposed to the best interests of
the corporation, and, with respect to any criminal action or proceeding, had no
reasonable cause to believe his or her conduct was unlawful. In the case of an
action by or in the right of the corporation, no indemnification may be made in
respect to any claim, issue or matter as to which such person shall have been
adjudged to be liable to the corporation unless and only to the extent that the
Court of Chancery or the court in which such action or suit was brought shall
determine that despite the adjudication of liability, but in view of all the
circumstances of the case, such person is fairly and reasonably entitled to
indemnity for such expenses that the court shall deem proper. Section 145
further provides that to the extent a director or officer of a corporation has
been successful in the defense of any action, suit or proceeding referred to
above, or in defense of any claim, issue or matter therein, he or she shall be
indemnified against expenses (including attorney's fees) actually and reasonably
incurred by him or her in connection therewith.
 
        The Registrant's Certificate of Incorporation provides that the
Registrant shall, to the fullest extent permitted by law, indemnify all
directors, officers, employees and agents of the company. The Certificate of
Incorporation also contains a provision eliminating the liability of directors
of the Registrant to the Registrant or its stockholders for monetary damage,
except under certain circumstances. the Certificate of Incorporation also
permits the Registrant to maintain insurance to protect itself and any director,
officer, employee or agent against any liability with respect to which the
Corporation would have the power to indemnify such persons under the Delaware
General Corporation Law. The Registrant maintains an insurance policy insuring
its directors and officers against certain liabilities.
 
                                     II-1

<PAGE>   64

<TABLE> 
ITEM 16. EXHIBITS.

<S>        <C>
 1.1       Form of Underwriting Agreement (to be filed by amendment)
 3.1(1)    Certificate of Incorporation, as amended
 3.2(2)    By-laws, as amended
 4.1(3)    Specimen Certificate for Shares of Common Stock
 5.1       Opinion of Testa, Hurwitz & Thibeault (to be filed by amendment)
23.1       Consent of Coopers & Lybrand L.L.P. (filed herewith)
23.2       Consent of Testa, Hurwitz & Thibeault (included in Exhibit 5.01)
24.1       Power of Attorney (contained on Signature Page)
 
<FN>
- ---------------
 
(1) Incorporated herein by reference to the exhibits to the Company's
    Registration Statement on Form S-8 (File No. 33-13953).
 
(2) Incorporated herein by reference to the Company's Annual Report on Form 10-K
    for the fiscal year ended September 30, 1987.
 
(3) Incorporated herein by reference to the exhibits to the Company's
    Registration Statement on Form S-1 (File No. 33-5312).

</TABLE>


 
ITEM 17. UNDERTAKINGS.
 
        The registrant hereby undertakes that, for purposes of determining any
liability under the Securities Act of 1933, each filing of the registrant's
annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act
of 1934 (and, where appropriate, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934)
that is incorporated by reference in the Registration Statement shall be deemed
to be a new registration statement relating to the securities offered therein,
and the offering of such securities at that time shall be deemed to be the
initial bona fide offering thereof.
 
        Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the registrant pursuant to the foregoing provisions or otherwise, the
registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Securities Act of 1933 and is, therefore, unenforceable. In the event that a
claim for indemnification against such liabilities (other than the payment by
the registrant of expenses incurred or paid by a director, officer, or
controlling person of the registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act of 1933 and will be governed by the final adjudication of such
issue.
 
        The undersigned registrant hereby undertakes that:
 
                (1) For purposes of determining any liability under the 
        Securities Act of 1933, the information omitted from the form of 
        prospectus filed as part of this registration statement in reliance 
        upon Rule 430A and contained in a form of prospectus filed by the 
        registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the 
        Securities Act shall be deemed to be part of this registration 
        statement as of the time it was declared effective.
 
                (2) For the purpose of determining any liability under the 
        Securities Act of 1933, each post-effective amendment that contains a 
        form of prospectus shall be deemed to be a new registration statement 
        relating to the securities offered therein, and the offering of such 
        securities at that time shall be deemed to be the initial bona fide 
        offering thereof.
 
                                     II-2

<PAGE>   65
 

                                   SIGNATURES
 
     Pursuant to the requirements of the Securities Act, the Registrant,
Advanced Magnetics, Inc., certifies that it has reasonable grounds to believe
that it meets all the requirements for filing on Form S-3 and has duly caused
this Registration Statement to be signed on its behalf by the undersigned,
thereunto duly authorized, in the City of Boston, Commonwealth of Massachusetts
on March 18, 1996.
 
                                         ADVANCED MAGNETICS, INC.
 
                                         By: /S/  JEROME GOLDSTEIN
                                             -----------------------------------
                                            JEROME GOLDSTEIN, CHAIRMAN OF THE
                                              BOARD OF DIRECTORS, PRESIDENT 
                                                        AND TREASURER
 
                        POWER OF ATTORNEY AND SIGNATURES
 
     We, the undersigned officers and directors of Advanced Magnetics, Inc.
hereby severally constitute and appoint Jerome Goldstein our true and lawful
attorney with full power to him singly to sign for us and in our names in the
capacities indicated below the Registration Statement on Form S-3 filed herewith
and any and all pre-effective and post-effective amendments to said Registration
Statement, and, in connection with any registration of additional securities
pursuant to Rule 462(b) under the Securities Act, to sign any abbreviated
registration statement and any and all amendments thereto, and to file the same,
with all exhibits thereto and other documents in connection therewith, in each
case, with the Securities and Exchange Commission, and generally to do all such
things in our names and on our behalf in our capacities as officers and
directors to enable Advanced Magnetics, Inc. to comply with the provisions of
the Securities Act, and all requirements of the Securities and Exchange
Commission, hereby ratifying and confirming our signatures as they may be signed
by our said attorney to said Registration Statement and any and all amendments
thereto.
 
     Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed below by the following persons in the capacities and
on the dated indicated.
 

<TABLE>
<CAPTION>
                SIGNATURE                              TITLE(S)                     DATE
                ---------                              --------                     ----
<S>                                         <C>                                <C>
/S/  JEROME GOLDSTEIN                       Chairman of the Board of           March 18, 1996
- ------------------------------------------  Directors, President and
             JEROME GOLDSTEIN               Treasurer (Principal Executive
                                            and Financial Officer)

/S/  ANTHONY P. ANNESE                      Vice President--Finance            March 18, 1996
- ------------------------------------------  (Principal Accounting Officer)
            ANTHONY P. ANNESE

/S/  THOMAS COOR                            Director                           March 18, 1996
- ------------------------------------------
              THOMAS COOR

/S/  LESLIE GOLDSTEIN                       Director                           March 18, 1996
- ------------------------------------------
           LESLIE GOLDSTEIN

/S/  RICHARD L. MCINTIRE                    Director                           March 18, 1996
- ------------------------------------------
          RICHARD L. MCINTIRE
</TABLE>

 
                                      II-3

<PAGE>   66
 

<TABLE>
<CAPTION>
                SIGNATURE                              TITLE(S)                     DATE
                ---------                              --------                     ----
<S>                                         <C>                                <C>
/S/  EDWARD B. ROBERTS                      Director                           March 18, 1996
- ------------------------------------------
            EDWARD B. ROBERTS

/S/  ROGER E. TRAVIS                        Director                           March 18, 1996
- ------------------------------------------
             ROGER E. TRAVIS

/S/  GEORGE M. WHITESIDES                   Director                           March 18, 1996
- ------------------------------------------
          GEORGE M. WHITESIDES
</TABLE>

 
                                      II-4

<PAGE>   67

<TABLE>

                                 EXHIBIT INDEX
<CAPTION>
EXHIBITS                                                                                    PAGE
- --------                                                                                    ----
  <S>       <C>                                                                          
   1.1      Form of Underwriting Agreement (to be filed by amendment)..................
   3.1(1)   Certificate of Incorporation, as amended...................................
   3.2(2)   By-laws, as amended........................................................
   4.1(3)   Specimen Certificate for Shares of Common Stock............................
   5.1      Opinion of Testa, Hurwitz and Thibeault (to be filed by amendment).........
  23.1      Consent of Coopers & Lybrand L.L.P. (filed herewith).......................
  23.2      Consent of Testa, Hurwitz & Thibeault (included in Exhibit 5.01)...........
  24.1      Power of Attorney (contained on Signature Page)............................
<FN> 
- ---------------
(1) Incorporated herein by reference to the exhibits to the Company's Registration 
    Statement on Form S-8 (File No. 33-13953).
 
(2) Incorporated herein by reference to the Company's Annual Report on Form 10-K for the 
    fiscal year ended September 30, 1987.
 
(3) Incorporated herein by reference to the exhibits to the Company's Registration 
    Statement on Form S-1 (File No. 33-5312).
</TABLE>
  





<PAGE>   1
 
                                                                    EXHIBIT 23.1
 
                      CONSENT OF INDEPENDENT ACCOUNTANTS
 
        We consent to the inclusion and incorporation by reference in this
registration statement on Form S-3 of our report dated November 8, 1995 on our
audits of the financial statements of Advanced Magnetics, Inc. We also consent
to the references to our firm under the caption "Experts" and "Selected
Financial Data."
 
                                          COOPERS & LYBRAND L.L.P.
 
Boston, Massachusetts
March 15, 1996