Seattle Genetics prices underwritten public offering of 10,000,000 shares of common stock

Seattle Genetics, Inc. today announced the pricing of an underwritten public offering of 10,000,000 shares of its common stock, offered at a price to the public of $15.50 per share. The gross proceeds to Seattle Genetics from this offering are expected to be $155,000,000, before deducting underwriting discounts and commissions and other estimated offering expenses payable by Seattle Genetics. Seattle Genetics has granted the underwriters a 30-day option to purchase up to an aggregate of 1,500,000 additional shares of common stock to cover overallotments, if any. All of the shares in the offering are to be sold by Seattle Genetics. The offering is expected to close on or about February 7, 2011, subject to customary closing conditions.

Jefferies & Company, Inc. and J.P. Morgan Securities LLC are acting as joint book-running managers for the proposed offering. Leerink Swann LLC and RBC Capital Markets, LLC are acting as co-lead managers for the proposed offering. Needham & Company, LLC, William Blair & Company, LLC, Oppenheimer & Co. Inc. and ThinkEquity LLC are acting as co-managers for the proposed offering.

Seattle Genetics anticipates using the net proceeds from the offering to fund potential regulatory approval of brentuximab vedotin and continuing preparations for the potential commercial launch of brentuximab vedotin, to fund Seattle Genetics' research and development efforts, including clinical trials and manufacturing campaigns for its product candidates, and for working capital and general corporate purposes.

A shelf registration statement relating to the shares was filed with the Securities and Exchange Commission and is effective. A preliminary prospectus supplement related to the offering has been filed with the SEC and is available on the SEC's website located at www.sec.gov. Copies of the final prospectus supplement relating to these securities, when available, may be obtained from Equity Syndicate Prospectus Department, Jefferies & Company, Inc., 520 Madison Avenue, 12th Floor, New York, NY, 10022, at 877-547-6340, and at [email protected], or from J.P. Morgan Securities LLC, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, New York 11717 or by calling 1-866-803-9204.

Source: Seattle Genetics