ImmunoGen Announces Proposed Public Offering of Common Stock

WALTHAM, Mass.--( BUSINESS WIRE)-- ImmunoGen, Inc.(Nasdaq: IMGN), a leader in the expanding field of antibody-drug conjugates (ADCs) for the treatment of cancer, today announced that it intends to offer and sell, subject to market and other conditions, 12,000,000 shares of its common stock in an underwritten public offering.

ImmunoGen also intends to grant the underwriters a 30-day option to purchase up to an additional fifteen percent (15%) of the shares of common stock offered in the public offering. All of the shares of common stock to be sold in the offering are to be offered by ImmunoGen.