AstraZeneca’s chief medical officer suddenly left his job Wednesday to become the chief executive officer of an unnamed, smaller biotech company, according to BioSpace.com.

Briggs Morrison, AstraZeneca’s chief medical officer and head of global late-stage drug development, is scheduled to leave immediately. The company notified his colleagues prior to the announcement, BioSpace.com said.

“It’s a great opportunity for him,” a spokeswoman told media outlets Wednesday, though she declined to name Morrison’s new company.

Morrison joined AstraZeneca in 2012 and has concentrated on streamlining and updating its drug portfolio and boosting the company’s research and development efforts to a budget of $5.6 billion in 2014, up from the $4.8 billion it spent in 2013, BioSpace.com notes.

He played a critical role in fighting off a takeover by Pfizer last year, when AstraZeneca rejected a $118 billion bid. Because Morrison had worked at Pfizer for five years as an executive, he said at the time he believed he had a unique insight into why the two companies wouldn’t be a great fit.

“At every one of our senior executive meetings here, a third of the agenda is pipeline, science, and business development,” Morrison told the New York Times when speaking about AstraZeneca. “I didn’t have a feeling at Pfizer that every layer of the company was science based.”

Source: BioSpace.com