Chris Viehbacher, who was GlaxoSmithKline's top executive in Research Triangle Park before becoming CEO of Sanofi, was fired by the French pharmaceutical company's board of directors this week.
Viehbacher, 54, who ran Sanofi for nearly six years, was a hit with investors but ran afoul of the board.
The company's chairman, Serge Weinberg, told reporters that Viehbacher failed to keep the board in the loop on a plan to sell an $8 billion portfolio of mature products, among other missteps, according to Bloomberg News.
"It's very unfortunate," Josep Ayami, chief investment officer of equities at Merchbanc in Spain, told Bloomberg. "He's done a good job as CEO, and you want stability and continuity in management."
On Viehbacher's watch, Sanofi acquired biotechnology company Genzyme for $20 billion in 2011. The company's stock more than doubled during his tenure and hit a new high just a few weeks ago.
Viehbacher left GSK in 2008, where he was president of U.S. pharmaceuticals, after being passed over for the CEO's job. He moved to Paris when he joined Sanofi but relocated to the Boston area earlier this year - a move that triggered consternation in France.