FORM OF UNDERWRITING AGREEMENT (Equity Primary Offering; Over Allotment Option; S-3) SEATTLE GENETICS, INC. 10,000,000 Shares of Common Stock Underwriting AgreementUnderwriting Agreement • January 18th, 2008 • Seattle Genetics Inc /Wa • Biological products, (no disgnostic substances) • New York
Seattle Genetics, Inc., a Delaware 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 10,000,000 shares of common stock, par value $0.001 per share, of the Company (the “Underwritten Shares”) and, at the option of the Underwriters, up to an additional 1,500,000 shares of common stock 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 of the Company to be outstanding after giving effect to the sale of the Shares are herein referred to as the “Stock”.
