A US federal court may have thrown a spanner into the workings of the hepatitis C virus (HCV) therapy market after siding with Merck & Co in a patent dispute.
The jury in the lawsuit upheld Merck’s claim that Gilead’s sofosbuvir – which features in its massive-selling Sovaldi and Harvoni HCV drugs – infringes two patents it holds alongside Ionis Pharmaceuticals (formerly known as Isis Pharma).
The consequences of the ruling remain unclear but in principle could mean that Gilead is forced to hand over to Merck a portion of Sovaldi and Harvoni sales revenues – which reached $12.5bn last year. Merck is asking for $2bn in damages and a 10% cut on all future sales of sofosbuvir-based products.
Gilead is however expected to take the case to the Court of Appeals for the Federal Circuit (CAFC) for further ruling.
Merck recently launched its own HCV therapy – Zepatier (elbasvir and grazoprevir) – in direct competition to Gilead’s franchise and said in a statement that it felt the outcome “reflected the evidence in the case”.
The patent dispute dates back to August 2013, when Merck first contacted Gilead requesting that the company pay royalties on sofosbuvir and obtain a license to the two patents – Nos. 7,105,499 and 8,481,712.
In the same month Gilead filed a lawsuit seeking a declaratory judgment that the Merck patents are invalid and not infringed on the basis that they “cover compounds which do not include, but may relate to, sofosbuvir”.
Gilead alleged in the lawsuit that Merck had amended its patent application in an attempt to extend its coverage to include sofosbuvir.
Gilead is also in the throes of a lawsuit with AbbVie, which claims it holds patents infringed by Harvoni. Gilead filed to invalidate the patents in December 2013.
Meanwhile, several groups have filed opposition to Gilead’s European patents for sofosbuvir that expires in 2028.