Amgen will acquire worldwide rights to Otezla (apremilast), Celgene’s treatment for psoriasis and psoriatric arthritis, for $13.4 billion, the companies announced.

Otezla is approved to treat patients with moderate-to-severe plaque psoriasis, adult patients with active psoriatic arthritis, and adult patients with ulcers associated with Behçet's Disease, a rare disorder causing inflammation in blood vessels.

Celgene’s divestment of the drug will clear the way for a $74 billion merger between Bristol-Myers Squibb and Celgene without facing potential antitrust litigation.