Bristol-Myers said on Monday it expects the deal to close by 2019 end. The company in June offered to sell Otezla to allay concerns raised by U.S. antitrust regulators, with an analyst valuing a deal for the drug at about $9 billion at the time.
The psoriasis drug brought in sales of $1.61 billion last year. Amgen said it expected Otezla sales to grow at least in the low-single digits over the next five years.
The deal for Otezla and certain related assets and liabilities is valued at $11.2 billion, net of the present value of $2.2 billion in future cash tax benefits. Bristol-Myers Squibb said it was increasing a previously planned $5 billion accelerated share buyback to $7 billion.
Its shares rose 5.2% and those of Celgene gained 3.7% in trading before the opening bell, while Amgen fell about 1%.