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): September 19, 2002 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.) 128 Sidney Street, Cambridge, Massachusetts 02139 (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code: (617) 995-2500 ITEM 9. REGULATION FD DISCLOSURE On September 19, 2002, the Registrant filed its Annual Report on Form 10-K for the fiscal year ended June 30, 2002 with the Securities and Exchange Commission. In connection with the filing of the Form 10-K, attached hereto as exhibits are certifications of the Registrant's Chief Executive Officer and Chief Financial Officer, as required by 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. These certifications are being furnished herewith solely to accompany the Form 10-K, pursuant to 18 U.S.C. Section 1350, are not being filed for purposes of Section 18 of the Securities Exchange Act of 1934, as amended and are not to be incorporated by reference into any of the Registrant's filings with the Securities and Exchange Commission, whether filed prior to or after the furnishing of these certifications, regardless of any general or specific incorporation language in any such filing. ITEM 7. FINANCIAL STATEMENTS AND EXHIBITS (c) Exhibits. 99.1 Certification Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (Subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code) 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: September 19, 2002 /S/ GREGG D. BELOFF ------------------------------- Gregg D. Beloff Chief Financial Officer and Vice President