A jury in U.S. District Court in Delaware has ordered Gilead Sciences to pay Merck & Co. $2.54 billion in damages because its hepatitis C drugs Sovaldi and Harvoni infringe on a Merck patent. The patent was originally awarded to Idenix Pharmaceuticals, which Merck acquired in 2014. The amount of the award is 10% of the drugs’ sales through August 2016. An active ingredient in both drugs is sofosbuvir, which Gilead obtained as part of its acquisition of the biotech firm Pharmasset in 2011. The dispute centers on whether Pharmasset derived sofosbuvir from an Idenix patent or whether it developed the compound itself. Gilead says it will appeal. The two drug companies sparred in a previous lawsuit in California, where a federal jury awarded Merck $200 million earlier this year. The award was overturned in June after allegations surfaced that a Merck attorney had lied under oath. Merck is contesting the overturned verdict.