Biogen Idec says that Thomas Bucknum, the firm’s executive vice president and general counsel, has resigned from his position, with immediate effect.

A press release from the US company gave little away, but the resignation comes just days after questions arose over revelations that Mr Bucknum and several other Biogen Idec executives had reaped millions of dollars from share sales in the days before the company suspended sales of its new multiple sclerosis drug, Tysabri (natalizumab) [[02/03/05b]]. The company and partner Elan Corporation, took the product off the market after reports of a rare central nervous system disease – known as progressive multifocal leukoencephalopathy – in two patients taking Tysabri together with Biogen Idec’s older MS drug, Avonex (interferon beta-1a), in a clinical trial [[01/03/05a]].

A US Securities and Exchange Commission filing last week revealed that Mr Bucknum had sold 89,700 shares on February 18 – the same day that Biogen Idec notified the US Food and Drug Administration of the PML cases – making a $1.9 million dollar profit [[02/03/05b]]. However, at the time, the company rejected claims of insider trading.