ImmunoGen(IMGN) - 2020 Q4 - Annual Report

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the year ended December 31, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the period from to Commission file number 0-17999 ImmunoGen, Inc. Massachusetts (State or other jurisdiction of incorporation or organization) 04-2726691 (I.R.S. Employer Identification No.) ...