August 27, 2008

Seattle Genetics to Present at Upcoming Investor Conferences

Seattle Genetics, Inc. (Nasdaq: SGEN) announced today that Clay B. Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics, will present at two upcoming investor conferences. The presentations will be webcast live and available for replay from Seattle Genetics' website,, under the "news and investor information" section.

Thomas Weisel Partners 2008 Healthcare Conference

Wednesday, September 3, 2008 at 3:50 p.m. Eastern Time. The conference is being held at The Four Seasons Hotel in Boston.

Morgan Stanley Global Healthcare Unplugged Conference

Tuesday, September 9, 2008 at 11:30 a.m. Eastern Time. The conference is being held at The Grand Hyatt Hotel in New York.

About Seattle Genetics

Seattle Genetics is a clinical stage biotechnology company focused on the development and commercialization of monoclonal antibody-based therapies for the treatment of cancer and autoimmune disease. The company has four product candidates in ongoing clinical trials: SGN-40, SGN-33, SGN-35 and SGN-70. SGN-40 is being developed under a worldwide collaboration with Genentech. In addition, the company has developed proprietary antibody-drug conjugate (ADC) technology comprising highly potent synthetic drugs and stable linkers for attaching the drugs to monoclonal antibodies. Seattle Genetics has collaborations for its ADC technology with a number of leading biotechnology and pharmaceutical companies, including Genentech, Bayer, CuraGen, Progenics, Daiichi Sankyo and MedImmune, a subsidiary of AstraZeneca, as well as an ADC co-development agreement with Agensys, a subsidiary of Astellas Pharma.