Amgen Inc. on Monday announced it will acquire Otezla, a Celgene Corp. psoriasis drug, for $13.4 billion in cash.

The Thousand Oaks biotech giant entered into an agreement with Celgene, which is expected to merge with New York’s Bristol-Myers Squibb Co.

Otezla is the only oral, non-biologic treatment for psoriasis and psoriatic arthritis, Amgen said in a statement.

Last year Otezla had sales of $1.6 billion . Amgen expects to grow sales through global expansion and new indications, “with expectations for Otezla to realize at least low double-digit sales growth, on average, over the next five years,” the company said in a statement.

“The acquisition of Otezla offers a unique opportunity for Amgen to provide patients an innovative oral therapy for psoriasis and psoriatic arthritis that fits squarely within our portfolio and complements our Enbrel and Amgevita brands,” Robert Bradway, chief executive at Amgen, said in a statement. “We will take advantage of our 20 years of experience in inflammatory disease to realize the full global potential of Otezla as an affordable option for patients with these serious, chronic inflammatory conditions.”

Shares of Amgen (AMGN) closed Monday up $6.33, or 3.2 percent, to $205.41 on the Nasdaq.