ImmunoGen, Inc. 6,250,000 Shares of Common Stock, par value $0.01 per share Underwriting AgreementUnderwriting Agreement • July 12th, 2012 • Immunogen Inc • Pharmaceutical preparations • New York
ImmunoGen, Inc., a Massachusetts corporation (the “Company”), proposes to issue and sell to the several Underwriters listed in Schedule 1 hereto (the “Underwriters”), for whom you are acting as representatives (the “Representatives”), an aggregate of 6,250,000 shares of Common Stock, par value $0.01 per share, of the Company (the “Underwritten Shares”) and, at the option of the Underwriters, up to an additional 937,500 shares of Common Stock, par value $0.01 per share, of the Company (the “Option Shares”). The Underwritten Shares and the Option Shares are herein referred to as the “Shares”. The shares of Common Stock, par value $0.01 per share, of the Company to be outstanding after giving effect to the sale of the Shares are referred to herein as the “Stock”.
