1
================================================================================
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, D.C.20549
                                 --------------

                                    FORM 8-K

                                 CURRENT REPORT
                                 --------------



                         PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
                     --------------------------------------


         Date of Report (Date of earliest event reported): May 16, 2000


                                 IMMUNOGEN, INC.
             (Exact name of registrant as specified in its Charter)


     Massachusetts                  0-17999                       04-2726691
     -------------                ------------                ----------------
(State or Other Jurisdiction      (Commission                   (IRS Employer
     of Incorporation             File Number)               Identification No.)


              333 Providence Highway, Norwood, Massachusetts 02062
              ----------------------------------------------------
              (Address of principal executive offices) (Zip Code)

       Registrant's telephone number, including area code: (781) 769-4242






================================================================================
                                   Page 1 of 6
  2
ITEM 5. OTHER EVENTS. On May 16, 2000, ImmunoGen, Inc. announced the appointment
        of Mark Skaletsky to its Board of Directors.



The press release  announcing the appointment of Mr. Skaletsky to the ImmunoGen,
Inc. Board of Directors is incorporated herein by reference and filed as exhibit
99.1 hereto.


ITEM 7.   FINANCIAL STATEMENTS AND EXHIBITS

(C)       Exhibits.

          99.1 The Registrant's Press Release dated May 16, 2000.

















                                   Page 2 of 6

  3




                               SIGNATURE

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




                                          ImmunoGen, Inc.
                                          (Registrant)


Date:     May 16, 2000                    /s/Kathleen A. Carroll
                                          --------------------------------------
                                          Kathleen A. Carroll
                                          Vice President, Finance and
                                            Administration, and principal
                                            financial officer










                                   Page 3 of 6
    4



EXHIBIT INDEX


Exhibit                                                             Sequential
Number                             Description                    Page Number(s)

99.1                     The Registrant's Press Release
                         dated May 16, 2000                              5



























                                   Page 4 of 6

  1
                                                                    Exhibit 99.1



IMMUNOGEN CONTACT:           Mitchel Sayare, Ph.D.
                             Chairman and CEO
                             ImmunoGen, Inc.
                             (781)769-4242
                             www.immunogen.com


FOR IMMEDIATE RELEASE


               ImmunoGen, Inc. Appoints Mark Skaletsky of GelTex
                  Pharmaceuticals, Inc. to Board of Directors

CAMBRIDGE,  Mass., May 16 -- ImmunoGen,  Inc.  (Nasdaq:  IMGN - news) named Mark
Skaletsky  to its Board of  Directors.  Mr.  Skaletsky  is CEO and  President of
GelTex  Pharmaceuticals,  Inc. GelTex develops and markets non- absorbed polymer
drugs that selectively bind and eliminate target  substances from the intestinal
tract.

"We are  genuinely  pleased to have Mark join our Board at this pivotal time in
ImmunoGen's  development,"  stated Mitchel Sayare,  Ph.D.,  Chairman and CEO of
ImmunoGen,  Inc. "The extensive experience and perspective Mark brings with him
will be a real asset as we establish  arrangements  with other companies for the
use of our technology with their monoclonal antibodies."

Mr.  Skaletsky  said,  "This is an exciting time to  participate in ImmunoGen's
development. With its novel Tumor-Activated Prodrug approach to cancer treatment
and the potential  development  of  additional  Tumor-Activated  Prodrugs  using
ImmunoGen's technology and antibodies from other sources, ImmunoGen is poised to
become a substantially  different  company. I look forward to the opportunity of
adding the value of my experience to the future of ImmunoGen."

Mr.  Skaletsky has been  President and CEO of GelTex  Pharmaceuticals,  Inc., of
Waltham,  MA since 1993.  Prior to that he was  President,  CEO and  Chairman of
Enzytech,  Inc.,  and  President  and COO of Biogen,  Inc.  Mr.  Skaltesky  is a
chairman of the board of directors of the Biotechnology  Industry  Organization,
and is a director of Isis Pharmaceuticals and Microcide. He is also a Trustee of
Bentley College.

ImmunoGen,  Inc. develops  innovative  biopharmaceuticals,  primarily for cancer
treatment. The Company has created potent Tumor-Activated  Prodrugs,  consisting
of low-molecular weight chemicals coupled to monoclonal antibodies, for delivery
to and destruction of cancer cells.

This press release  includes  forward-looking  statements  based on management's
current  expectations.  Factors  that  could  cause  future  results  to  differ
materially from such expectations  include,  but are not limited to: the ability
to secure future funding;  the success of the Company's research  strategy;  the
applicability of the discoveries made therein; the difficulties  inherent in the
development of  pharmaceuticals,  including  uncertainties  as to the timing and
results  of  preclinical  studies;  uncertainty  as  to  whether  the  Company's
potential  products will succeed in human clinical  trials and uncertainty as to
the results of such trials; uncertainty as to whether adequate reimbursement for
these  products  will exist from  government,  private  healthcare  insurers and
third-party  payors; and the uncertainties as to the extent of future government
regulation of the pharmaceutical business.

                                       ###