Gilead Sciences Inc. will have to pay Merck & Co. Inc. $200 million for infringing Merck’s patent on Gilead’s blockbuster hepatitis C medications.

Although large in absolute terms, the award represents only a fraction of the damages Merck and collaboration partner Ionis Pharmaceuticals Inc. had sought to recover. Merck was asking for a 10 percent royalty on Gilead’s Sovaldi and Harvoni medications, which had rung up sales of $20 billion as of Dec. 31.