Pfizer to acquire Biohaven Pharmaceuticals in $11.6B cash deal

US-based multinational biotechnology firm Pfizer announced Tuesday it will acquire Biohaven Pharmaceuticals in an $11.6 billion cash deal.

The two companies have entered into a definitive agreement, in which the boards of directors of both firms unanimously approved the transaction.

Pfizer will pay $148.50 per share in cash to buy outstanding shares of Biohaven, according to a statement.

Despite closing Monday with a 7.9% decline, Biohaven's stock price soared 70.2% to $141.50 per share on the New York Stock Exchange during pre-market hours on Tuesday.

Biohaven is best known for developing a migraine therapy for acute treatment and prevention of migraine in adults.