Seagen Inc. announced on November 8, 2022, the Board of Directors of Company appointed David R. Epstein as a member of the Board, in each case effective as of November 9, 2022. Mr. Epstein will serve as a Class II director for a term expiring at the 2024 annual meeting of the Company's stockholders and until his successor has been duly elected and qualified, or until his earlier death, resignation or removal. On the Start Date, Mr. Epstein assumed the duties and responsibilities of the Company's principal executive officer from Roger D. Dansey, M.D., who was serving as the Interim Chief Executive Officer of the Company since May 5, 2022 until the Start Date.

There is no arrangement or understanding with any person pursuant to which Mr. Epstein was appointed as the Chief Executive Officer of the Company and/or as a member of the Board. Mr. Epstein, age 61, most recently served as an executive partner at Flagship Pioneering from January 2017 to October 2022. From January 2010 to July 2016, he served as Chief Executive Officer of Novartis Pharmaceuticals, a division of Novartis AG.

Previously, Mr. Epstein started and led Novartis' Oncology and Molecular Diagnostic units. Mr. Epstein has extensive public and private company board experience, and currently serves on the board of directors of Evelo Biosciences Inc., OPY Acquisition Corp. I and Senti Biosciences Inc. Mr. Epstein previously served as Chairman of the board of directors of Evelo Biosciences Inc. from September 2019 to June 2022.

He also previously served as Chairman and as a member of the board of directors of Axcella Health Inc. from December 2017 to October 2022 and of Rubius Therapeutics Inc. from January 2017 to October 2022. Mr. Epstein also served on the board of International Flavors and Fragrances from January 2016 to January 2021. Mr. Epstein holds a B.S. Degree in Pharmacy from Rutgers University College of Pharmacy and an M.B.A. in Finance and Marketing from the Columbia University Graduate School of Business.

Dr. Dansey has served as Interim Chief Executive Officer of the Company since May 5, 2022 and as the Company's Chief Medical Officer since May 2018. On November 8, 2022, the Company entered into an amended and restated employment agreement with Dr. Dansey in connection with his employment as President, Research and Development of the Company, commencing November 9, 2022. Dr. Dansey will also continue to serve as Chief Medical Officer of the Company.

On November 8, 2022, the Board appointed Sandra M. Swain, M.D. to the Board, effective November 9, 2022. Dr. Swain will serve as a Class III director for a term expiring at the 2025 annual meeting of the Company's stockholders and until her successor has been duly elected and qualified, or until her earlier death, resignation or removal. Dr. Swain has more than 30 years of breast cancer clinical research experience.

She currently serves as Associate Dean for Research Development and Professor of Medicine at Georgetown University Medical Center and is the Vice President of Genetic Medicine for MedStar Health. She is also on the Conquer Cancer Foundation Board of American Society of Clinical Oncology (ASCO) and chairs the Women Who Conquer Cancer committee. Prior to her current roles at Georgetown University and MedStar Health, Dr. Swain held roles at the National Cancer Institute, National Institutes of Health, the Washington Cancer Institute at MedStar Washington Hospital Center, and FDA Oncologic Drugs Advisory Committee.

She is a fellow of the American College of Physicians and ASCO. Dr. Swain has served on ASCO's board of directors and is a past president (2012-2013). She has published over 335 articles, including many regarding clinical trials in breast cancer.

Dr. Swain holds an M.D. from the University of Florida and a B.A. in Chemistry from the University of North Carolina.