Biogen Stock Falls After CEO’s Resignation

Biogen Inc., one of the world’s biggest biotechnology companies, said Chief Executive and President James Tobin has unexpectedly resigned, sending its shares tumbling as much as 19%. Tobin will be succeeded by Chairman James L. Vincent. Shares of Biogen, which hit a 52-week high on Tuesday, fell $7.06 to $79.81 in heavy Nasdaq trading. Tobin and Biogen agreed not to elaborate on the reasons for Tobin’s departure, said Vincent, who was president of the company from 1985 to 1994 and CEO from 1985 to 1997. The Cambridge, Mass.-based company did well under Tobin’s five years in a leadership role. The company turned its multiple sclerosis drug Avonex into a blockbuster, boosting Biogen shares more than 100% this year to make it the best performer among large biotech companies.