Drugmakers Regeneron Pharmaceuticals and Sanofi have said they will appeal a decision by a US federal jury that their cholesterol drug Praluent (alirocumab) infringes patents owned by US biotech firm Amgen.

Amgen filed the lawsuit with the US District Court of Delaware in 2014, charging that the drug infringed on patents pertaining to its own cholesterol drug, Repatha.

New York-based Regeneron and France’s Sanofi said they continue to believe Amgen's patents for antibodies targeting PCSK9 (proprotein convertase subtilisin/kexin type 9) are invalid.

A hearing is scheduled to take place to consider a permanent injunction.

Praluent, the first PCSK9 inhibitor to be approved for use in the US, was launched in that market in autumn of 2015 by the transatlantic partnership. It had total sales of $11 million for the year. The two companies said the Delaware decision would not impact deliveries to physicians and patients.