agreed to buy Vega Therapeutics Inc. for as much as $2 billion to gain potential new treatments for bleeding disorders. Under the deal, Incyte will pay Vega’s parent, the closely held , $1.25 billion upfront and as much as $750 million in additional payments for achieving certain milestones, according to a statement Monday. The acquisition bolsters Incyte’s product pipeline as its top drug, the blood cancer treatment Jakafi, faces patent expiration in a few years, eroding its revenue.