* Mullen to retire effective June 8
* Biogen initiates search for successor
LOS ANGELES, Jan 4 (Reuters) - Biogen Idec (BIIB.O) said on Monday that James Mullen will retire as president and chief executive officer from the biotechnology company as of June 8.
Mullen will also retire from Biogen’s board at the completion of his current term as a director at the company’s 2010 annual shareholder meeting, Biogen said in a statement.
The company, based in Cambridge, Massachusetts, said it has initiated a search for Mullen’s successor.
Shares of Biogen, which makes the multiple sclerosis drugs Avonex and Tysabri, rose 14 cents to close at $53.64 on Nasdaq and gained another 30 cents at $53.94 in after-hours trading.
The company has struggled to overcome concerns about the safety of its most important drug, Tysabri, which has been associated with a potentially deadly brain infection known as PML.
Tysabri was temporarily withdrawn from the market in 2005 after being linked with PML. It was reintroduced in July 2006 with stricter safety warnings, but concerns continue to hold back sales.
Last year, dissident shareholder Carl Icahn managed to place two directors on Biogen’s board following a contentious proxy battle.
Icahn has also accused Biogen of sabotaging its own announced attempt to find a buyer.
Reporting by Deena Beasley; Editing by Richard Chang