WALTHAM, Mass.--(BUSINESS WIRE)--ImmunoGen, Inc. (Nasdaq: IMGN), a biopharmaceutical company that develops targeted anticancer therapeutics, announced today that it intends to offer, subject to market and other conditions, 5,000,000 shares of its common stock in an underwritten public offering. ImmunoGen expects to grant the underwriters a thirty (30) day option to purchase up to 750,000 additional shares to cover over-allotments, if any.
