UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                             -----------------------

                                    FORM 10-Q

     /X/  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
          EXCHANGE ACT OF 1934

                FOR THE QUARTERLY PERIOD ENDED DECEMBER 31, 2000
                                       OR

     / /  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
          EXCHANGE ACT OF 1934

 FOR THE TRANSITION PERIOD FROM _____________________ TO ______________________


                         COMMISSION FILE NUMBER 0-17999
                             ----------------------

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


                 MASSACHUSETTS                             04-2726691
- ---------------------------------------------          ------------------
(State or other jurisdiction of incorporation           (I.R.S. Employer
               or organization)                        Identification No.)

                                128 SIDNEY STREET
                               CAMBRIDGE, MA 02139
          ------------------------------------------------------------
          (Address of principal executive offices, including zip code)

                                 (617) 995-2500
              ----------------------------------------------------
              (Registrant's telephone number, including area code)


              ----------------------------------------------------
             (Former name, former address and former fiscal year, if
                          changed since last report.)

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

Yes X   No
   ---     ---

     Indicate the number of shares outstanding of each of the issuer's classes
of common stock, as of the latest practicable date.

     At February 13, 2001 there were 38,521,214 shares of common stock, par
value $.01 per share, of the registrant outstanding.

                            EXHIBIT INDEX AT PAGE 18



                                 IMMUNOGEN, INC.
                                TABLE OF CONTENTS




                                                                                                                 PAGE
                                                                                                                 ----
                                                                                                           
PART I. FINANCIAL INFORMATION

Item 1. Condensed Consolidated Financial Statements:

        a. Condensed Consolidated Balance Sheets as of December 31, 2000 and June 30, 2000........................ 3

        b. Condensed Consolidated Statements of Operations for the three months and six months ended
           December 31, 2000 and 1999............................................................................. 4

        c. Condensed Consolidated Statements of Stockholders' Equity for the year ended June 30, 2000 and the
           six months ended December 31, 2000..................................................................... 5

        d. Condensed Consolidated Statements of Cash Flows for the six months ended December 31, 2000 and 1999.... 6

        e. Notes to Condensed Consolidated Financial Statements................................................... 7

Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations..................... 13

Item 3. Quantitative and Qualitative Disclosures about Market Risk................................................ 17

PART II. OTHER INFORMATION........................................................................................ 17

SIGNATURES........................................................................................................ 19




                                       2


                                 IMMUNOGEN, INC.
                      CONDENSED CONSOLIDATED BALANCE SHEETS
                    AS OF DECEMBER 31, 2000 AND JUNE 30, 2000
                                   (UNAUDITED)



                                                                                               DECEMBER 31,         JUNE 30,
                                                                                                  2000                2000
                                                                                            -----------------------------------
                                                                                                              
                                                   ASSETS
Cash and cash equivalents.................................................................       $142,148,970       $1,408,908
Marketable securities.....................................................................         16,312,353       15,920,484
Due from related parties..................................................................             17,274           47,352
Prepaid and other current assets..........................................................            308,069          415,441
                                                                                            -----------------------------------
Total current assets......................................................................        158,786,666       17,792,185

Property and equipment, net of accumulated depreciation...................................          2,644,534        1,508,396
Other assets..............................................................................             43,700           43,700
                                                                                            -----------------------------------
             Total Assets.................................................................       $161,474,900      $19,344,281
                                                                                            ===================================

                                   LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable..........................................................................           $620,923         $891,419
Accrued compensation......................................................................            171,294          204,210
Other current accrued liabilities.........................................................          1,243,125          987,475
Current portion of capital lease obligations..............................................             34,005           60,083
Current portion of deferred revenue.......................................................            540,000          325,000
                                                                                            -----------------------------------
             Total current liabilities....................................................          2,609,347        2,468,187

Capital lease obligations.................................................................              2,820            8,137
Deferred Revenue..........................................................................          6,000,000        1,500,000
                                                                                            -----------------------------------
              Total liabilities...........................................................          8,612,167        3,976,324

Stockholders' equity:
  Common stock, $.01 par value; authorized 50,000,000 shares as of December 31, 2000 and
  June 30, 2000; issued and outstanding 38,487,931 shares and 33,050,659 shares as of
  December 31, 2000 and June 30, 2000, respectively.......................................            384,879          330,507
Additional paid-in capital................................................................        310,827,880      168,682,991
Accumulated deficit.......................................................................       (158,992,455)    (153,955,925)
Accumulated other comprehensive income....................................................            642,429          310,384
                                                                                            -----------------------------------
              Total stockholders' equity..................................................        152,862,733       15,367,957
                                                                                            -----------------------------------
              Total liabilities and stockholders' equity..................................       $161,474,900      $19,344,281
                                                                                            ===================================



          The accompanying notes are an integral part of the condensed
                       consolidated financial statements.


                                       3



                                 IMMUNOGEN, INC.
                 CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
      FOR THE THREE MONTHS AND SIX MONTHS ENDED DECEMBER 31, 2000 AND 1999
                                   (UNAUDITED)



                                                                     THREE MONTHS ENDED                  SIX MONTHS ENDED
                                                                         DECEMBER 31,                       DECEMBER 31,
                                                                         ------------                       ------------
                                                                    2000              1999              2000            1999
                                                                    ----              ----              ----            ----
                                                                                                            
        Revenues:
           Revenue earned under collaboration agreement.........       $526,000        $2,500,000       $2,285,000      $6,500,000
           Development fees.....................................        100,069                            100,069           4,800
           Licensing............................................              -               195                -             485
                                                                 ------------------------------------------------------------------
                 Total revenues.................................        626,069         2,500,195        2,385,069       6,505,285

        Expenses:
           Research and development.............................      3,619,171         1,890,695        7,188,049       3,721,716
           General and administrative...........................      1,047,265           643,212        1,901,990       1,146,278
                                                                 ------------------------------------------------------------------
                  Total expenses................................      4,666,436         2,533,907        9,090,039       4,867,994

        Net earnings/(loss) from operations.....................     (4,040,367)          (33,712)      (6,704,970)      1,637,291
           Gain/(loss) on the sale of assets....................              -             1,645          (1,900)           1,488
           Interest income, net.................................      1,242,923            69,931        1,456,526         123,958
           Other income.........................................        248,706            42,030          268,814          42,030
                                                                 ------------------------------------------------------------------
        Net earnings/(loss) before income tax expense and
            minority interest...................................     (2,548,738)           79,894       (4,981,530)      1,804,767

           Income tax expense...................................         55,000                 -           55,000               -
                                                                 ------------------------------------------------------------------
        Net earnings/(loss) before minority interest............     (2,603,738)           79,894       (5,036,530)      1,804,767

           Minority interest in net loss of consolidated
              subsidiary........................................              -            25,290                -          50,580
                                                                 ------------------------------------------------------------------

        Net earnings/(loss).....................................   $ (2,603,738)         $105,184      $(5,036,530)     $1,855,347
                                                                 ==================================================================
        Earnings/(loss) per common share:
          Basic.................................................         $(0.07)            $0.00           $(0.14)          $0.07
                                                                 ==================================================================

          Diluted...............................................         $(0.07)            $0.00           $(0.14)          $0.06
                                                                 ==================================================================
        Average common shares outstanding:
          Basic.................................................     36,408,516        27,143,460       34,854,392      26,528,658
                                                                 ==================================================================

    Diluted.....................................................     36,408,516        33,463,758       34,854,392      32,848,956
                                                                 ==================================================================



          The accompanying notes are an integral part of the condensed
                       consolidated financial statements.


                                       4



                                 IMMUNOGEN, INC.
            CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
   FOR THE YEAR ENDED JUNE 30, 2000 AND THE SIX MONTHS ENDED DECEMBER 31, 2000
                                   (UNAUDITED)


                                                                            ADDITIONAL
                                     COMMON STOCK       PREFERRED STOCK       PAID-IN        ACCUMULATED
                                   SHARES      AMOUNT    SHARES   AMOUNT      CAPITAL          DEFICIT
                                   ------      ------    ------   ------      -------          -------
                                                                          
Balance at June 30, 1999........ 25,668,797   $256,687    2,400      $24    $158,790,821    $(153,718,365)

Unrealized gains on marketable
Securities, net.................          -          -        -        -               -                -
Net loss for the year ended
  June 30, 2000.................          -          -        -        -               -         (237,560)

Comprehensive Income............          -          -        -        -               -                -

Stock Options exercised.........    131,567      1,316        -        -         219,192                -
Exercise of put option..........  1,023,039     10,231        -        -       2,489,769                -
Warrants exercised..............  3,403,728     34,037        -        -       4,408,575                -
Conversion of Series E
  Convertible Preferred Stock
  into Common Stock.............  2,823,528     28,236  (2,400)     (24)         (28,212)               -
Compensation for stock option
  vesting acceleration for
  terminated officer............          -          -        -        -         349,716                -
Value ascribed to ImmunoGen
  warrants issued to BioChem,
  net of financing costs........          -          -        -        -       2,453,130                -
                                 ------------------------------------------------------------------------
Balance at June 30, 2000........ 33,050,659   $330,507        -       $-    $168,682,991    $(153,955,925)
                                 ========================================================================

Unrealized gains on marketable
Securities, net.................          -          -        -        -               -                -
Net loss for the six months
  ended Dec 31, 2000............          -          -        -        -               -       (5,036,530)

Comprehensive loss..............          -          -        -        -               -                -

Stock Options exercised.........    266,456      2,664        -        -         701,695                -
Warrants exercised..............    381,342      3,813        -        -       1,706,735                -
Issuance of Common Stock to
  Abgenix.......................    789,474      7,895        -        -      14,992,105                -
Issuance of Common Stock to
  Public, net of financing
  costs.........................  4,000,000     40,000        -        -     124,744,354                -
                                 ------------------------------------------------------------------------
Balance at December 31, 2000     38,487,931   $384,879        -       $-    $310,827,880    $(158,992,455)
                                 ========================================================================


                                   ACCUMULATED
                                      OTHER     COMPREHENSIVE      TOTAL
                                  COMPREHENSIVE    INCOME      STOCKHOLDERS'
                                     INCOME        (LOSS)         EQUITY
                                     ------        ------         ------
                                                      
Balance at June 30, 1999........         $-              $-    $5,329,167

Unrealized gains on marketable
   Securities, net..............     310,384        310,384       310,384
Net loss for the year ended
  June 30, 2000.................          -        (237,560)     (237,560)
                                                -----------

Comprehensive Income............          -          72,824             -
                                                ===========
Stock Options exercised.........          -               -       220,508
Exercise of put option..........          -               -     2,500,000
Warrants exercised..............          -               -     4,442,612
Conversion of Series E
  Convertible Preferred Stock
  into Common Stock.............          -               -             -
Compensation for stock option
  vesting acceleration for
  terminated officer............          -               -       349,716
Value ascribed to ImmunoGen
  warrants issued to BioChem,
  net of financing costs........          -               -     2,453,130
                                  ---------------------------------------

Balance at June 30, 2000........   $310,384              $-   $15,367,957
                                  =======================================

Unrealized gains on marketable
  Securities, net...............    332,045         332,045       332,045
Net loss for the six months
  ended Dec 31, 2000............          -      (5,036,530)   (5,036,530)
                                               ------------
Comprehensive loss..............          -      (4,704,485)
                                               ============
Stock Options exercised.........          -               -       704,359
Warrants exercised..............          -               -     1,710,548
Issuance of Common Stock to               -               -    15,000,000
  Abgenix.......................
Issuance of Common Stock to
  Public, net of financing                -               -   124,784,354
  costs.
                                  ---------------------------------------
Balance at December 31, 2000       $642,429              $-  $152,862,733
                                  =======================================


          The accompanying notes are an integral part of the condensed
                       consolidated financial statements.

                                      5


                                 IMMUNOGEN, INC.
                 CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
               FOR THE SIX MONTHS ENDED DECEMBER 31, 2000 AND 1999
                                   (UNAUDITED)



                                                                                            SIX MONTHS ENDED
                                                                                              DECEMBER 31,
                                                                                         2000               1999
                                                                                         ----               ----
                                                                                                     
Cash flows from operating activities:
 Net earnings/(loss) to common stockholders........................................   $ (5,036,530)        $1,855,347
 Adjustments to reconcile net loss to net cash used for operating activities:
  Depreciation and amortization....................................................        252,056            244,567
  (Loss)/Gain on sale of property and equipment....................................          1,900             (1,488)
  Tax benefit from stock options exercised.........................................              -             13,419
  Minority interest in net loss of consolidated subsidiary.........................              -            (50,580)
  Amortization of deferred lease...................................................              -            (26,376)
  Changes in operating assets and liabilities:
         Due from related parties..................................................         30,078         (2,478,607)
         Prepaid and other current assets..........................................        107,372            (32,163)
         Accounts payable..........................................................       (270,494)           (58,174)
         Accrued compensation......................................................        (32,917)          (136,475)
         Deferred revenue..........................................................      4,715,000                  -
         Other current accrued liabilities.........................................        253,750             (2,870)
                                                                                   -----------------------------------
              Net cash provided by (used for) operating activities.................         20,215           (673,400)

Cash flows from investing activities:
  Payments received on note receivable.............................................              -            350,000
  Purchase of marketable securities................................................       (391,869)        (4,022,915)
  Proceeds from maturities of marketable securities................................              -                  -
  Unrealized gain on cash and cash equivalents.....................................        332,045
  Proceeds from sale of property and equipment.....................................              -              1,745
  Capital expenditures.............................................................     (1,388,193)          (143,947)
                                                                                   -----------------------------------
    Net cash (used for) investing activities.......................................     (1,448,017)        (3,815,117)

Cash flows from financing activities:
  Proceeds from Common Stock issuance, net.........................................    139,784,354          3,545,814
  Proceeds from issuance of subsidiary convertible preferred stock, net............              -          1,686,000
  Proceeds from Stock Options exercised, net.......................................        704,359                  -
  Proceeds from Warrants exercised, net............................................      1,710,548                  -
  Principal payments on capital lease obligations..................................        (31,397)           (27,407)
                                                                                   -----------------------------------
    Net cash provided by financing activities......................................    142,167,864          5,204,407
                                                                                   -----------------------------------
Net change in cash and cash equivalents............................................    140,740,062            715,890

Cash and cash equivalents, beginning balance.......................................      1,408,908          4,225,580
                                                                                   -----------------------------------
Cash and cash equivalents, ending balance..........................................   $142,148,970         $4,941,470
                                                                                   ===================================

Supplemental disclosures:

Due from related party for quarterly investment payment............................             $-           $843,000

Cash paid for taxes................................................................        $55,000                 $-

Cash paid for interest.............................................................         $4,362            $10,131


          The accompanying notes are an integral part of the condensed
                       consolidated financial statements.

                                       6


                                 IMMUNOGEN, INC.
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

A. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES


NATURE OF BUSINESS

         ImmunoGen, Inc. ("ImmunoGen" or the "Company") was incorporated in
Massachusetts in 1981 to develop, produce and market commercial anti-cancer and
other pharmaceuticals based on molecular immunology. The Company continues to
research and develop its various products and technologies, and does not expect
to derive revenue from commercially approved product sales within the
foreseeable future. It is anticipated that the Company's existing capital
resources, enhanced by collaborative agreement funding, will enable current and
planned operations to be maintained for the foreseeable future. However, if the
Company is unable to achieve subsequent milestones under its collaborative
agreements (See Note B), the Company may be required to defer or limit some or
all of its research, development and/or clinical projects.

         The Company is subject to risks common to companies in the
biotechnology industry including, but not limited to, the development by the
Company or its competitors of new technological innovations, dependence on key
personnel, protection of proprietary technology, manufacturing and marketing
limitations, collaboration arrangements, third-party reimbursements and
compliance with governmental regulations.

BASIS OF PRESENTATION

         The accompanying condensed consolidated financial statements at
December 31, 2000 and June 30, 2000 and for the three-month and six-month
periods then ended include the accounts of the Company and its subsidiaries,
ImmunoGen Securities Corp. and Apoptosis Technology, Inc. ("ATI"). Although the
condensed consolidated financial statements are unaudited, they include all of
the adjustments, consisting only of normal recurring adjustments, which
management considers necessary for a fair presentation of the Company's
financial position in accordance with generally accepted accounting principles
for interim financial information. Certain information and footnote disclosures
normally included in the Company's annual financial statements have been
condensed or omitted. The preparation of interim financial statements requires
the use of management's estimates and assumptions that affect the reported
amounts of assets and liabilities and disclosure of contingent assets and
liabilities at the date of the interim financial statements and the reported
amounts of revenues and expenditures during the reported period. The results of
the interim periods are not necessarily indicative of the results for the entire
year. Accordingly, the interim financial statements should be read in
conjunction with the audited financial statements and notes thereto included in
the Company's Annual Report on Form 10-K for the year ended June 30, 2000.

CASH AND CASH EQUIVALENTS

         The Company considers all investments purchased with maturity dates of
three months or less from the date of acquisition to be cash equivalents.

MARKETABLE SECURITIES

         In accordance with the Company's investment policy, surplus cash is
invested in investment-grade corporate and U.S. Government debt securities
typically with maturity dates of less than one year. The Company determines the
appropriate classification of marketable securities at the time of purchase and
reevaluates such designation as of each balance sheet date. Marketable
securities which meet the criteria for classification as available-for-sale are
carried at fair value based on quoted market prices. Unrealized gains and losses
are reported net, as comprehensive income, within shareholders' equity. The cost
of debt securities is adjusted for amortization of premiums and accretion of
discounts to maturity with all amortization/accretion included in interest
income.

                                       7


As of December 31, 2000 and June 30, 2000, $142,148,970 and $1,408,908,
respectively in cash, overnight government repurchase agreements and other
investments maturing in three months or less were classified as cash and cash
equivalents. The Company's cash, cash equivalents and marketable securities as
of December 31, 2000 are as follows:



                                                                          GROSS          GROSS
                                       AMORTIZED        UNREALIZED      UNREALIZED     ESTIMATED
                                          COST             GAINS          LOSSES       FAIR VALUE
                                          ----             -----          ------       ----------
                                                                           
Cash and money market funds.........  $16,037,958           $   -           $   -      $16,037,958
Commercial paper....................   86,978,182         621,818                       87,600,000
Government treasury notes...........   45,405,388          20,611                       45,425,998
Non-government issues...............    9,397,366                                        9,397,366
                                     --------------------------------------------------------------
      Total.........................  157,818,894         642,429                      158,461,323
Less amounts classified as cash and
      cash equivalents.............. (141,511,515)       (637,455)              -     (142,148,970)
                                     --------------------------------------------------------------

Total marketable securities.........  $16,307,379          $4,974           $   -       $16,312,353
                                     ==============================================================


         No realized gains or losses on available-for-sale securities were
recognized during the three- and six-month periods ended December 31, 2000.

COMPUTATION OF LOSS PER COMMON SHARE

         Basic and diluted earnings/(loss) per share is calculated based upon
the weighted average number of common shares outstanding during the period.
Diluted earnings per share incorporate the dilutive effect of stock options,
warrants and other convertible securities. ImmunoGen Common Stock equivalents,
as calculated in accordance with the treasury-stock accounting method, equaled
5,329,604 and 6,320,298 as of December 31, 2000 and 1999 respectively. ImmunoGen
Common Stock equivalents have not been included in the loss per share
calculation for the six months ended December 31, 2000 because their effect is
anti-dilutive. Components of calculating net earnings/(loss) per share are set
forth in the following table:



                                                                       SIX MONTHS ENDED
                                                                         DECEMBER 31,
                                                                     --------------------
                                                                     2000            1999
                                                                     ----            ----
                                                                              
Net earnings/(loss) to common shareholders.....................    $(5,036,530)     $1,855,347
                                                                ===============================

Weighted average common shares outstanding, basic..............      34,854,392     26,528,658
Net effect of dilutive instruments:
  Convertible preferred stock..................................         518,698      4,692,984
  Options......................................................       2,588,225      1,234,384
  Warrants.....................................................       2,222,681        392,930
                                                                -------------------------------

Weighted average common shares outstanding, diluted............      40,183,996     32,848,956
                                                                ===============================
Earnings/(loss) per common share, basic........................         $(0.14)          $0.07
                                                                ===============================
Earnings/(loss) per common share, dilutive.....................         $(0.14)          $0.06
                                                                ===============================



                                       8



                                 IMMUNOGEN, INC.
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

COMPREHENSIVE INCOME/(LOSS)

         The Company presents comprehensive income in accordance with Statement
of Financial Accounting Standard No. 130, "Reporting Comprehensive Income." For
the six-month period ended December 31, 2000 total comprehensive loss equaled
$4,704,485. Comprehensive income was comprised entirely of net income/(loss) and
unrealized gains recognized on available-for-sale debt securities.

RECENT ACCOUNTING PRONOUNCEMENTS

         In December 1999, the Securities and Exchange Commission ("SEC") issued
Staff Accounting Bulletin 101 ("SAB 101"), which addresses accounting policies
to be applied in the recognition, presentation and disclosure of revenues from
contract partnerships, in financial statements to be filed with the SEC. The net
effect of SAB 101, when applicable, could defer into future accounting periods
revenue recognition for some milestone payments previously received. On June 26,
2000, the SEC deferred the implementation of SAB 101 from the second calendar
quarter of 2000 until no later than the fourth calendar quarter of 2000, in
order to provide companies with additional time to determine the effect that a
change in accounting policy under SAB 101 will have on their revenue recognition
practices. The implementation of SAB 101 will require companies to report any
changes in accounting principle at the time of implementation in accordance with
Accounting Principles Board Opinion No. 20, "Accounting Changes." The
implementation of SAB 101 could have a material effect on the reported financial
results for the year ended June 30, 2001.


B. AGREEMENTS

         In February 1999, the Company entered into an exclusive license
agreement with SmithKline Beecham plc, London and SmithKline Beecham,
Philadelphia, wholly-owned subsidiaries of GlaxoSmithKline, (collectively, "SB")
to develop and commercialize ImmunoGen's lead tumor activated prodrug ("TAP"),
huC242-DM1 (the "SB Agreement"). Under the terms of the agreement, the Company
could receive up to $41.5 million, subject to the achievement by the Company of
certain development milestones. The Company is also entitled to receive royalty
payments on future product sales, if and when they commence. Finally, at
ImmunoGen's option, SB will purchase up to $5.0 million of ImmunoGen Common
Stock over the next two years, subject to certain conditions. Through December
2000, SB had purchased $2.5 million worth of ImmunoGen Common Stock.

         The SB Agreement is expected to provide the Company with sufficient
cash funding to carry out its responsibilities in developing
huC242-DM1/SB-408075. To that end, the Company will be responsible for certain
costs associated with the Phase I/II clinical study, which was initiated in
December 1999. All costs subsequent to this Phase I/II clinical study will be
the responsibility of SB.

         As of December 31, 2000, the Company had received five milestones
totaling $11.5 million under the SB Agreement. All the milestones have been
recorded as collaboration revenue, with the exception of $140,000 of the fourth
milestone, which has been recorded as deferred revenue until such time as the
remaining ongoing commitments associated with this milestone have been
satisfied.

         In May 2000, the Company executed two separate licensing agreements
with Genentech, Inc. of South San Francisco, California. The first agreement
grants an exclusive license to Genentech for ImmunoGen's TAP technology for use
with antibodies such as Herceptin(R). Under the terms of the agreement,
Genentech will receive exclusive worldwide rights to commercialize anti-HER2
targeting products using ImmunoGen's maytansinoid TAP platform. Genentech will
be responsible for manufacturing, product development and marketing of any
products resulting from the agreement; ImmunoGen will be reimbursed for any
preclinical and clinical materials that it makes under the agreement. ImmunoGen
received and recorded as revenue a $2.0 million non-refundable payment for
execution of the

                                       9



agreement for which no further performance is required. In addition to royalties
on net sales, the terms of the agreement include certain other payments based
upon Genentech's achievement of milestones, assuming all benchmarks are met, for
potentially up to nearly $40.0 million.

         In addition to the Herceptin(R) agreement described above, the Company
announced in May 2000 that it has entered into an additional agreement with
Genentech. This second collaboration provides Genentech with broad access to
ImmunoGen's maytansinoid TAP technology for use with Genentech's other
proprietary antibodies. This multi-year agreement provides Genentech with a
license to utilize ImmunoGen's maytansinoid TAP platform in its antibody product
research efforts and an option to obtain product licenses for a limited number
of antigen targets over the agreement's five-year term. Under this agreement,
the Company received and recorded as revenue a non-refundable technology access
fee of $3.0 million in May 2000. This agreement also provides for certain other
payments based on Genentech's achievement of milestones, assuming all benchmarks
are met for potentially up to nearly $40.0 million per antigen target, and
royalties on net sales of resulting products. Genentech will be responsible for
manufacturing, product development and marketing of any products developed
through this collaboration; ImmunoGen will be reimbursed for any preclinical
materials that it makes under the agreement. The agreement can be renewed for
one subsequent three- year period, for an additional technology access fee.

         Also in May, 2000, the Company entered into a development,
commercialization and license agreement with British Biotech Pharmaceuticals
Limited ("British Biotech"), a biotechnology company located in Oxford, England,
to develop and commercialize the Company's huN901-DM1 TAP for the treatment of
small-cell lung cancer. The agreement grants British Biotech exclusive rights to
develop and commercialize huN901-DM1 in the European Union and Japan. The
Company retains the rights to commercialize huN901-DM1 in the United States and
the rest of the world, as well as the right to manufacture the product
worldwide. Under the terms of the agreement, British Biotech will be responsible
for conducting the clinical trials necessary to achieve marketing approval in
the United States, European Union and Japan. ImmunoGen is responsible for the
remaining preclinical development, and will be reimbursed for manufacturing the
product for clinical trials. British Biotech paid a fee of $1.5 million for its
territorial rights to huN901-DM1, which has been deferred, to be recorded as
revenue as the Company completes its preclinical development obligations. Upon
approval of the product for marketing in the United States, the Company will pay
to British Biotech a one-time milestone payment of $3.0 million. ImmunoGen will
receive royalties on sales of huN901-DM1 in the European Union and Japan.

         In September 2000, the Company entered into a collaboration agreement
with Abgenix. The agreement provides Abgenix with access to the Company's
maytansinoid TAP technology for use with Abgenix's antibodies along with options
to obtain product licenses for antigen targets. The Company has received a total
of $5.0 million in technology access fee payments and is entitled to potential
milestone payments and royalties on net sales of any resulting products. The
Company recorded $4.9 million of the technology access fees as deferred revenue
to be recognized over the period of the collaboration agreement. In addition, on
September 7, 2000, Abgenix purchased $15.0 million of the Company's common stock
in accordance with the agreement. Abgenix has the right to extend its options
for a specified period of time for an extension fee. Our agreement with Abgenix
will terminate after a specified time period during which the Company has given
Abgenix access to its technology ends. Either party can terminate the agreement
for any material breach by the other party that remains uncured for a certain
period of time.

         In September 2000, the Company entered into a collaboration agreement
with MorphoSys AG of Martinsried, Germany. Pursuant to this agreement, MorphoSys
will identify fully human antibodies against a specific cell surface marker that
the Company has identified through its apoptosis research and is associated with
a number of forms of cancer. The Company intends to develop products using
antibodies generated by MorphoSys against this marker. The Company paid
MorphoSys a $825,000 technology access payment, recorded as an R&D charge, and
will pay development-related milestone payments and royalties on net sales of
any resulting products. The Company reimburses MorphoSys for its research and
development efforts related to identifying these antibodies. During the quarter
ended December 31, 2000 the Company reimbursed Morphosys approximately $188,000.
The Company can terminate this agreement unilaterally at any time and either
party can terminate the agreement for any material breach by the other party
that remains uncured for a certain period of time.


                                       10



         During this quarter, in November 2000, the Company entered into a
collaboration agreement with Genzyme Transgenics Corporation of Framingham,
Massachusetts. Pursuant to this agreement, Genzyme Transgenics Corporation will
produce ImmunoGen's humanized monoclonal antibody, huN901. HuN901 is the
antibody component of ImmunoGen's tumor-activated prodrug (TAP), huN901-DM1,
being developed for treatment of small-cell lung cancer (SCLC). The Company paid
Genzyme Transgenics Corporation a $500,000 project start-up fee, recorded as an
R&D charge, and will pay development-related milestone payments and royalties on
net sales of any resulting products. The Company can terminate this agreement
unilaterally at any time and either party can terminate the agreement for any
material breach by the other party that remains uncured for a certain period of
time.


C. MINORITY INTEREST

         In July 1997, ATI entered into a collaboration agreement with BioChem
Pharma Inc. ("BioChem"), a large Canadian biopharmaceutical company. This
agreement granted BioChem an exclusive worldwide license to ATI's proprietary
screens based on two families of proteins involved in apoptosis, for use in
identifying leads for anti-cancer drug development. As of April 2000, BioChem
had fulfilled all of its funding obligations under the agreement by purchasing a
total of $11.125 million in non-voting, non-dividend-bearing convertible
preferred stock of ATI.

         In April 2000, BioChem informed ATI of its decision not to extend the
agreement beyond its scheduled July 31, 2000 termination date. Consequently,
under the terms of the agreement, rights to all screens delivered to BioChem
reverted to ATI effective August 1, 2000. However, certain provisions pertaining
to the license of any products resulting from the collaboration will remain in
force. As of August 1, 2000, no compound leads were identified.

         The preferred stock issued to BioChem is convertible into ATI common
stock at any time after three years from the date of first issuance, at a
conversion price equal to the then current market price of the ATI common stock,
but in any event at a price that will result in BioChem acquiring at least 15%
of the then outstanding ATI common stock. Through December 31, 2000, 11,125
shares of ATI preferred stock were issued to BioChem, representing a 15%
minority interest (on an if-converted and fully-diluted basis) in the net equity
of ATI. This minority interest portion of ATI's loss reduced ImmunoGen's net
loss in the three- and six-month periods ended December 31, 1999 by $25,290 and
$50,580, respectively. Based upon an independent appraisal, approximately 3% of
the $11.125 million invested, or approximately $334,000, was allocated to the
minority interest in ATI, with the remainder, or approximately $10.791 million
allocated to the Company's equity.

         As part of the BioChem agreement, BioChem also received warrants to
purchase shares of ImmunoGen Common Stock equal to the amount invested in ATI
during the three-year research term. Beginning July 31, 2000, these warrants
became exercisable for a number of shares of ImmunoGen Common Stock determined
by dividing $11.125 million, the amount of BioChem's investment in ATI, by the
market price of ImmunoGen Common Stock on the exercise date, subject to certain
limitations imposed by the Nasdaq Stock Market rules, which limit the sale or
issuance by an issuer of certain securities at a price less than the greater of
book or market value. Consequently, BioChem's ability to convert all of its
ImmunoGen warrants into ImmunoGen Common Stock is limited to a total of 20% of
the number of shares of ImmunoGen's Common Stock outstanding on the date of the
initial transaction to the extent that the conversion price would be less than
the market price of ImmunoGen Common Stock on that date, unless stockholder
approval for such conversion is obtained, if required, or unless the Company has
obtained a waiver of that requirement. The exercise price is payable in cash or
shares of ATI's preferred stock, at BioChem's option. The warrants are expected
to be exercised only in the event that the shares of ATI common stock do not
become publicly traded. ImmunoGen expects that BioChem will use its shares of
ATI preferred stock, in lieu of cash, to exercise the warrants.


                                       11


D. CAPITAL STOCK

         In November 2000, the Company completed a secondary offering of 4.0
million shares of Common Stock at $33.00 per share. Net proceeds to the Company
were $124.8 million. Proceeds from the secondary offering will be used to fund
current operations and invest in technologies and collaborations to increase the
number of potential products in the Company's internal pipeline.

         In July 2000, a holder of warrants originally issued in connection with
a private placement of the Company's Series A Convertible Preferred Stock
exercised his right to acquire 50,000 shares of Common Stock at $3.11 per share.
Proceeds from this warrant exercise will be used to fund current operations.

         In September 2000, a holder of warrants originally issued in connection
with a private placement of the Company's Series A Convertible Preferred Stock
exercised his right to acquire 50,000 shares of Common Stock at $3.11 per share.
Proceeds from this warrant exercise will be used to fund current operations.

         In September 2000, holders of warrants originally issued in
connection with a private placement of the Company's Series B Convertible
Preferred Stock exercised their rights to acquire 176,569 shares of Common
Stock at $5.49 per share. Proceeds from this warrant exercise will be used to
fund current operations.

         In September 2000, holders of warrants originally issued in
connection with a private placement of the Company's Series D Convertible
Preferred Stock exercised their rights to acquire 27,273 shares of Common
Stock at $1.94 per share. Proceeds from this warrant exercise will be used to
fund current operations.

         In October 2000, holders of warrants originally issued in connection
with a private placement of the Company's Series B Convertible Preferred
Stock exercised their rights to acquire 57,500 shares of Common Stock at
$5.49 per share. Proceeds from this warrant exercise will be used to fund
current operations.

         In October 2000, a holder of warrants originally issued in connection
with a private placement of the Company's Series A Convertible Preferred Stock
exercised his right to acquire 20,000 shares of Common Stock at $3.11 per share.
Proceeds from this warrant exercise will be used to fund current operations.

         During the six-month period ended December 31, 2000, holders of options
issued through the Company's Restated Stock Option Plan, as amended, exercised
their rights to acquire an aggregate of 266,456 shares at prices ranging from
$0.84 per share to $14.75 per share. The total proceeds from these option
exercises, $704,359, will be used to fund current operations.

E. SUBSEQUENT EVENTS

         In January 2001, the Company entered into a collaboration agreement
with Avalon, Inc. ("Avalon") of Gaithersburg, Maryland. Pursuant to the
agreement, Avalon will provide gene targets to the Company. The Company will be
responsible for the development, manufacture and commercialization of any
resulting products. The Company paid Avalon an up front fee. Either party can
terminate the agreement for any material breach by the other party that remains
uncured for a certain period of time.

         Also in January 2001, the Compensation Committee of the Board of
Directors of the Company established a calendar year bonus plan for the Company.
In consideration of the Company's achievements in calendar year 2000, the
Compensation Committee of the Board of Directors approved a bonus of
approximately $900,000 to all officers and employees of the Company. The bonus
was approved, and will be expensed and paid, in the Company's third fiscal
quarter ending March 31, 2001.

                                       12



                                 IMMUNOGEN, INC.

ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS


OVERVIEW

         Since our inception, we have been principally engaged in the
development of antibody based cancer therapeutics. Our product candidates,
tumor-activated prodrugs ("TAPs"), consist of an antibody chemically linked, or
conjugated, to a highly potent cell-killing, or cytotoxic agent which is
delivered directly to the tumor cell where it is released and activated. As of
December 31, 2000, our accumulated deficit was approximately $159.0 million. We
have incurred significant net losses since inception as a result of research and
development and general and administrative expenses in support of our
operations. We anticipate incurring net losses over at least the next several
years to continue development of our TAP technology and product candidates,
expand our operations, conduct clinical trials and apply for regulatory
approvals.

         We have established collaborative agreements that allow companies to
use our TAP technology to develop products with antibodies. We also have
licensed certain rights to our first two internally developed TAP product
candidates to companies that have product development and commercialization
capabilities we wish to access in exchange for fees, milestone payments and
royalties on product sales. Our collaborative partners include SmithKline
Beecham, Genentech, Abgenix, British Biotech, MorphoSys, Genzyme Transgenics and
Avalon. We expect that substantially all of our revenue for the foreseeable
future will result from payments under collaborative arrangements. The terms of
the collaborative agreements vary, reflecting the value we add to the
development of any particular product candidate.

         In September 2000, we entered into a collaboration agreement with
Abgenix, Inc. of Freemont, California. The agreement provides Abgenix with
access to our maytansinoid TAP technology for use with Abgenix's antibodies
along with options to obtain product licenses for antigen targets. Through
December 31, 2000, we have received a total of $5.0 million in technology access
fee payments. We are also entitled to potential milestone payments and royalties
on net sales of any resulting products. In addition, on September 7, 2000,
Abgenix purchased $15.0 million of our common stock in accordance with the
agreement. Abgenix has the right to extend its product license options for a
specified period of time for an extension fee. Our agreement with Abgenix will
terminate once the specified time period during which we have given Abgenix
access to our technology ends. Either party can terminate the agreement for any
material breach by the other party that remains uncured for a certain period of
time.

         In September 2000, we entered into a collaboration agreement with
MorphoSys AG of Martinsried, Germany. Pursuant to this agreement, MorphoSys will
identify fully human antibodies against a specific cell surface marker that we
have identified through our apoptosis research and which is associated with a
number of forms of cancer. We intend to develop products using antibodies
generated by MorphoSys against this marker. We paid MorphoSys an $825,000
technology access payment, recorded as an R&D charge, and will pay
development-related milestone payments and royalties on net sales of any
resulting products. We can terminate this agreement unilaterally at any time and
either party can terminate the agreement for any material breach by the other
party remains uncured for a certain period of time.

         During this quarter, in November 2000, we entered into a collaboration
agreement with Genzyme Transgenics Corporation of Framingham, Massachusetts.
Pursuant to this agreement, Genzyme Transgenics Corporation will produce our
humanized monoclonal antibody, huN901. HuN901 is the antibody component of our
tumor-activated prodrug (TAP), huN901-DM1, being developed for treatment of
small-cell lung cancer (SCLC). We paid Genzyme Transgenics Corporation a
$500,000 project start-up fee, recorded as an R&D charge, and will pay
development-related milestone payments and royalties on net sales of any
resulting products. We can terminate this agreement unilaterally at any time and
either party can terminate the agreement for any material breach by the other

                                       13



party that remains uncured for a certain period of time.

         In January 2001, we entered into a collaboration agreement with Avalon,
Inc. of Gaithersburg, Maryland. Pursuant to the agreement, Avalon will provide
us gene targets. We will be responsible for the development, manufacture and
commercialization of any resulting products. We paid Avalon an up front fee.
Either party can terminate the agreement for any material breach by the other
party that remains uncured for a certain period of time.



RESULTS OF OPERATIONS


COMPARISON OF THREE MONTHS ENDED DECEMBER 31, 2000 AND 1999

REVENUES

         We earn revenue from our collaborations, development fees and licensing
fees. Total revenues for the three months ended December 31, 2000 decreased 75%
to $626,000 from $2.5 million for the three months ended December 31, 1999. Our
largest revenue source is our collaboration revenue, which accounted for
substantially all of our revenue in both three-month periods. The decrease in
revenues from the three month period ended December 31, 1999 to the three month
period ended December 31, 2000 was primarily attributable to the deferral of
certain collaboration technology access payments that we received and that will
be recognized over the period during which we fulfill our commitments under a
certain collaboration agreement.

EXPENSES

 RESEARCH AND DEVELOPMENT EXPENSES. Research and development expenses for the
three months ended December 31, 2000 increased 91% to $3,619,000 from $1,891,000
for the three months ended December 31, 1999. This increase primarily derives
from our efforts to develop new products for our internal pipeline and includes
payments made in connection with the MorphoSys and Genzyme Transgenics
agreements. We expect that future research and development expenses will
significantly increase in connection with the further development of new TAP
product candidates.

 GENERAL AND ADMINISTRATIVE EXPENSES. General and administrative expenses for
the three months ended December 31, 2000 increased 63% to $1,047,000 from
$643,000 for the three months ended December 31, 1999. This increase was
primarily due to increased business development and investor relations efforts.
Future general and administrative expenses are also expected to increase in
connection with the continued development of our product candidates and
technologies.

INTEREST INCOME

         Interest income for the three months ended December 31, 2000 increased
to $1,243,000 from $70,000 for the three months ended December 31, 1999. The
increase in interest income from 1999 to 2000 is primarily attributable to
higher cash and investment balances resulting from our November 2000 secondary
stock offering, a collaborator investment of $15,000,000 and receipt of
$7,000,000 in collaborator milestone payments during the quarter ended December
31, 2000.

OTHER INCOME

         Other income for the three months ended December 31, 2000 increased to
$249,000 from $42,000 for the same period in the prior year. The increase is
attributable to $250,000 we received as a settlement in a securities litigation
case filed on our behalf.

                                       14


COMPARISON OF SIX MONTHS ENDED DECEMBER 31, 2000 AND 1999

REVENUES

         Total revenues for the six months ended December 31, 2000 decreased 65%
to $2,385,000 from $6,505,000 for the six months ended December 31, 1999. Our
largest revenue source is our collaboration revenue, which accounted for
substantially all of our revenue in both three-month periods. The decrease in
revenues from the six month period ended December 31, 1999 to the three month
period ended December 31, 2000 was primarily attributable to the deferral of
certain collaboration technology access payments that we received and that will
be recognized over the period during which we fulfill our commitments under a
certain collaboration agreement.

EXPENSES

 RESEARCH AND DEVELOPMENT EXPENSES. Research and development expenses for the
six months ended December 31, 2000 increased 93% to $7,188,000 from $3,722,000
for the six months ended December 31, 1999. This increase primarily relates to:
(i) our efforts to develop new products for our internal pipeline and includes
payments made in connection with the MorphoSys and Genzyme Transgenics
agreements and (ii) expenses related to the initiation and support of the our
second Phase I/II clinical trial of our small-cell lung cancer product,
huN901-DM1/BB-10901, coupled with ongoing support of our first Phase I/II
clinical trial of our colorectal cancer product, huC242-DM1/SB-408075. We expect
that future research and development expenses will significantly increase in
connection with the further development of new TAP product candidates.

 GENERAL AND ADMINISTRATIVE EXPENSES. General and administrative expenses for
the six months ended December 31, 2000 increased 66% to $1,902,000 from
$1,146,000 for the six months ended December 31, 1999. This increase was
primarily due to increased administrative and business development staffing as
well as increased expenditures associated with business development and investor
relations. Future general and administrative expenses are also expected to
increase in connection with the continued development of our product candidates
and technologies.

INTEREST INCOME

         Interest income for the six months ended December 31, 2000 increased to
$1,456,000 from $124,000 for the six months ended December 31, 1999. The
increase in interest income from 1999 to 2000 is primarily attributable to
higher cash and investment balances resulting from our November 2000 secondary
stock offering, a collaborator investment of $15,000,000 in September 2000 and
receipt of $7,000,000 in collaborator milestone payments during the quarter
ended December 31, 2000.

OTHER INCOME

         Other income for the six months ended December 31, 2000 increased to
$269,000 from $42,000 for the same period in the prior year. The increase is
attributable to $250,000 we received as a settlement in a securities litigation
case filed on our behalf.

LIQUIDITY AND CAPITAL RESOURCES

         As of December 31, 2000, we had approximately $158.5 million in cash
and short-term investments. In November 2000, we completed a secondary offering
of 4.0 million shares of our common stock. Net proceeds of the offering were
$124.8 million. We intend to use the net proceeds from the offering for working
capital and general corporate purposes, including research and development.
Since July 1, 2000, we have financed the net cash used to support operating
activities primarily from various collaborative and financing sources. These
sources include milestone revenues earned under our collaboration agreement with
SmithKline Beecham, the sale of equity securities to Abgenix, the exercise of
stock options and warrants to purchase Common Stock and income earned on
invested assets. For the six months ended December 31, 2000, we were cash flow
positive on an operational basis.


                                       15


         Net cash provided by operations during the six months ended December
31, 2000 was $20,000 compared to net cash used in operations of $673,000 in the
six months ended December 31, 1999. This decrease in operational cash use is
largely due to the timing of receipt of collaboration payments and higher
interest income, offset by increased operational expenses.

                  Net cash used in investing activities was $1.45 million for
the six months ended December 31, 2000, and primarily represents capital
expenditures. Capital purchases were $1.39 million for the six months ended
December 31, 2000, and consisted primarily of costs associated with the buildout
of our existing Norwood, Massachusetts development and pilot manufacturing
facility. We anticipate additional capital expenditures for the completion of
this project to be less than $300,000 over the next three months. Certain
capital outlays are expected to be reimbursed pursuant to our collaborative
agreements.

         Net cash provided by financing activities increased to $142.2 million
for the six months ended December 31, 2000 versus $5.2 million provided by
financing activities for the six months ended December 31, 1999. The increase is
largely due to our November 2000 secondary offering of 4.0 million shares of
common stock, the exercise of 381,342 warrants and 266,456 stock options during
the six-month period ended December 31, 2000 and the September 7, 2000 issuance
of 789,474 shares of our common stock to Abgenix. Our total proceeds from all
common stock issued for the six months ended December 31, 2000 were $142.2
million.

         We anticipate that our capital resources will enable us to meet our
operational expenses and capital expenditures for the foreseeable future. We
believe that the proceeds from our November 2000 secondary stock offering in
addition to our established collaborative agreements will provide funding
sufficient to allow us to meet our obligations under all collaborative
agreements while also allowing us to develop product candidates and technologies
not covered by collaborative agreements. However, we cannot assure you that such
collaborative agreement funding will, in fact, be realized. Should we not meet
some or all of the terms and conditions of our various collaboration agreements,
we may be required to pursue additional strategic partners, secure alternative
financing arrangements, and/or defer or limit some or all of our research,
development and/or clinical projects.

RECENT ACCOUNTING PRONOUNCEMENTS

         In December 1999, the Securities and Exchange Commission ("SEC") issued
Staff Accounting Bulletin 101 ("SAB 101"), which addresses accounting policies
to be applied in the recognition, presentation and disclosure of revenues from
contract partnerships, in financial statements to be filed with the SEC. The net
effect of SAB 101, when applicable, could defer into future accounting periods
revenue recognition for some milestone payments previously received. On June 26,
2000, the SEC deferred the implementation of SAB 101 from the second calendar
quarter of 2000 until no later than the fourth calendar quarter of 2000, in
order to provide companies with additional time to determine the effect that a
change in accounting policy under SAB 101 will have on their revenue recognition
practices. The implementation of SAB 101 will require companies to report any
changes in accounting principle at the time of implementation in accordance with
Accounting Principles Board Opinion No. 20, "Accounting Changes." The
implementation of SAB 101 could have a material effect on our reported financial
results for the year ended June 30, 2001.

CERTAIN FACTS THAT MAY AFFECT FUTURE RESULTS OF OPERATIONS

         This report contains certain forward-looking statements as that term is
defined in the Private Securities Litigation Reform Act of 1995. Such statements
are based on management's current expectations and are subject to a number of
factors and uncertainties which could cause actual results to differ materially
from those described in the forward-looking statements. The Company cautions
investors that there can be no assurance that actual results or business
conditions will not differ materially from those projected or suggested in such
forward-looking statements as a result of various factors, including, but not
limited to, the following: the uncertainties associated with preclinical studies
and clinical trials; the early stage of the Company's initial product
development and lack of product revenues; the Company's history of operating
losses and accumulated deficit; the Company's lack of commercial manufacturing

                                       16


experience and commercial sales, distribution and marketing capabilities;
reliance on suppliers of key materials necessary for production of the products
and technologies; the potential development by competitors of competing products
and technologies; the Company's dependence on existing and potential
collaborative partners, and the lack of assurance that the Company will receive
any funding under such relationships to develop and maintain strategic
alliances; the lack of assurance regarding patent and other protection for the
Company's proprietary technology; governmental regulation of the Company's
activities, facilities, products and personnel; the dependence on key personnel;
uncertainties as to the extent of reimbursement for the costs of the Company's
potential products and related treatments by government and private health
insurers and other organizations; the potential adverse impact of
government-directed health care reform; the risk of product liability claims;
and economic conditions, both generally and those specifically related to the
biotechnology industry. As a result, the Company's future development efforts
involve a high degree of risk.

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

         In the normal course of business, the financial position of the Company
is subject to certain risks, including market risk associated with interest rate
movements. The Company regularly assesses these risks and has established
policies and business practices designed to mitigate such exposures. The Company
invests surplus cash in low-risk debt securities, typically maturing in one year
or less, pending use in operations. The Company manages these funds by seeking
principal preservation while concurrently enhancing rates of return. The
Company's interest income is therefore sensitive to changes in the general level
of domestic interest rates. Based on the Company's overall interest rate
exposure at December 31, 2000, a near-term change in interest rates would not
materially affect the fair value of interest rate sensitive instruments.

                           PART II. OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS.

         The Company is not a party to any material legal proceedings.

ITEM 2. CHANGES IN SECURITIES AND USE OF PROCEEDS.


         In October 2000, holders of warrants originally issued in connection
with a private placement of the Company's Series B Convertible Preferred Stock
exercised their rights to acquire 57,500 shares of Common Stock at $5.49 per
share.
Proceeds from this warrant exercise will be used to fund current operations.

         In October 2000, a holder of warrants originally issued in connection
with a private placement of the Company's Series A Convertible Preferred Stock
exercised his right to acquire 20,000 shares of Common Stock at $3.11 per share.
Proceeds from this warrant exercise will be used to fund current operations.

         In November 2000, the Company completed a secondary offering of 4.0
million shares of Common Stock at $33.00 per share, before underwriters'
discounts. Net proceeds to the Company were $124.8 million. Proceeds from the
secondary offering will be used to fund current operations and invest in
technologies and collaborations to increase the number of potential products in
the Company's internal pipeline.

         In November 2000, the Company adjusted warrants, originally held in
connection with a private placement of convertible debentures, in accordance
with the anti-dilution provision of those warrants. The warrants, prior to
adjustment were for 2,185,660 shares of common stock at exercise prices between
$3.46 and $5.19 per share. The adjusted warrants are for 2,439,215 shares at
exercise prices between $3.31 and $4.97 per share. In addition, the Company
issued a five-year warrant for 340,000 shares of Common Stock at an exercise
price of $38.00 per share, in lieu of amending the warrants, in accordance with
their anti-dilution provisions, as a result of the Company's November 2000
secondary offering.

                                       17


         During the six-month period ended December 31, 2000, holders of options
issued through the Company's Restated Stock Option Plan, as amended, exercised
their rights to acquire an aggregate of 266,456 shares at prices ranging from
$0.84 per share to $14.75 per share. The total proceeds from these option
exercises, $704,359, will be used to fund current operations.

ITEM 3. DEFAULTS UPON SENIOR SECURITIES.

         Not applicable

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

         The Company's Annual Meeting of Shareholders was held on November 14,
         2000. At the meeting, the following matters were voted upon:

          (1)  The proposal to elect six (6) directors was approved by a vote of
               29,938,777 shares FOR and 56,626 shares WITHHELD.

          (2)  The following persons were elected as Directors of the Company
               and the record votes cast is as set forth below:



                  Name               Votes Cast           Votes For            Votes Withheld
         ----------------------- ------------------- --------------------- -----------------------
                                                                          
         Mitchel Sayare              29,995,403           29,938,577               56,826
         Walter A. Blattler          29,995,403           29,938,777               56,626
         David W. Carter             29,995,403           29,930,737               64,666
         Michael R. Eisensen         29,995,403           29,916,437               78,966
         Stuart F. Feiner            29,995,403           29,931,537               63,866
         Mark Skaletsky              29,995,403           29,905,077               90,326



ITEM 5. OTHER INFORMATION.

         Not applicable

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K.

         (a)  Exhibits

                    None.

         (b)  Reports on Form 8-K

                    Form 8-K dated October 10, 2000-Item 5: Other Events.
                    ImmunoGen, Inc. and MorphoSys announce a collaboration
                    agreement between the two companies for the discovery and
                    development by MorphoSys of human monoclonal antibodies
                    against certain specified ImmunoGen Targets.


                                       18




                                   SIGNATURES

         Pursuant to the requirements of the Securities Exchange Act of 1934, as
amended, the Registrant has duly caused this report to be signed on its behalf
by the undersigned thereunto duly authorized.

                                         IMMUNOGEN, INC.



                                     
Date: February 14, 2001               By:  /s/ Mitchel Sayare
                                           Mitchel Sayare
                                           President and Chief Executive Officer
                                           (principal executive and interim principal
                                           financial officer)

Date: February 14, 2001               By:  /s/ Virginia A. Lavery
                                           Virginia A. Lavery
                                           Sr. Corporate Controller
                                           (principal accounting officer)


                                       19