$295.7 Million

ImmunoGen, Inc.

Follow-on Offering

Bookrunner, December 2021

ImmunoGen, Inc.

ImmunoGen, Inc. (the “Company” or “ImmunoGen”) is a clinical-stage biotechnology company focused on developing the next generation of antibody-drug conjugates, or ADCs, to improve outcomes for cancer patients. By generating targeted therapies with enhanced anti-tumor activity and favorable tolerability profiles, the Company aims to disrupt the progression of cancer and offer patients more good days, calling this its commitment to “target a better now.” ImmunoGen’s lead program is mirvetuximab soravtansine (mirvetuximab), a first-in-class investigational ADC targeting FRα, a cell-surface protein over-expressed in a number of epithelial tumors, including ovarian, endometrial, and non-small-cell lung cancers.