Dr Morrissey will replace George Scangos, who has resigned to become president and CEO of Biogen Idec.
Dr Morrissey is currently working as a president of research and development at Exelixis. He joined Exelixis in 2000 and served as executive vice president, discovery, before his appointment as president of research and development in January 2007.
Stelios Papadopoulos, chairman of the board of directors, said: “Under the leadership of Drs Scangos and Morrissey, Exelixis has built one of the best R&D groups in the industry and has 14 compounds moving through development by our partners and ourselves.
“In Michael Morrissey we have a strong leader who has earned the respect of the Board and has been central to the company’s research and development efforts, which are the core of the company’s activities.”
Dr Morrissey said: “Under George’s leadership, we have worked hard to grow the company and advance the pipeline. The management team and I are confident in our employees and our ability to move forward in an effective and thoughtful manner and bring innovative new cancer therapies to patients.”
Exelixis is a development-stage biotechnology company dedicated to the discovery and development of novel small molecule therapeutics for the treatment of cancer and other serious diseases.