Data on retreatment experiences with brentuximab vedotin in clinical trials to be presented at 2010 ASCO

Seattle Genetics, Inc. (Nasdaq: SGEN) and Millennium: The Takeda Oncology Company today announced that data regarding retreatment experiences with brentuximab vedotin in phase I and phase II clinical trials will be presented during a poster session at the 2010 Annual Meeting of the American Society of Clinical Oncology (ASCO) being held June 4-8, 2010 in Chicago, Illinois. The presentation will highlight data from Hodgkin lymphoma and systemic anaplastic large cell lymphoma (ALCL) patients who have been retreated upon relapse after discontinuing previous brentuximab vedotin therapy.

Details of the ASCO presentation are below and the full abstract is available on the ASCO website at www.asco.org.

"Objective responses with brentuximab vedotin (SGN-35) retreatment in CD30-positive hematologic malignancies: A case series"

• Saturday, June 5, 2010, 8:00 a.m. to 12:00 p.m. Central Time
• Abstract # 8062
• Poster session: Lymphoma and plasma cell disorders
• First author: Dr. Nancy L. Bartlett, Siteman Cancer Center, Washington University, St. Louis, Missouri