The United States Court of Appeals for the Federal Circuit has stayed a permanent injunction for Sanofi’s and Regeneron Pharmaceuticals’ Praluent (alirocumab), an anti-cholesterol drug, a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, pending the companies’ appeal of the injunction. The permanent injunction had been issued in patent-infringement litigation brought by Amgen, which has a competing PCSK9 inhibitor, Repatha (evolocumab). Praluent (alirocumab) and Repatha (evolocumab) are monoclonal antibodies in a new class of anti-cholesterol drugs, PCSK9 inhibitors. As a result of the ruling, Sanofi and Regeneron will continue marketing, selling, and manufacturing Praluent in the US during the appeal process.

Sanofi and Regeneron are challenging both the injunction ruling and validity judgment during the appeal process. The companies believe that previously asserted patent claims by Amgen for antibodies targeting PCSK9 are invalid in Amgen’s ongoing US patent-infringement lawsuit against the partners.

In January 2017, Amgen was granted a permanent injunction by the United States District Court in Delaware that prohibited Sanofi and Regeneron from manufacturing, using, selling, or offering Praluent for sale in the US on the basis of Amgen’s claims that the companies infringed two patents that Amgen holds for its anti-cholesterol drug, Repatha (evolocumab). The ruling followed a jury verdict in March 2016 in Amgen’s favor in a trial on the validity of two Amgen patents that describe and claim monoclonal antibodies to PCSK9.

The injunction is not applicable outside the US or to clinical trials, which are continuing as planned, according to Sanofi. Outside the US, Praluent is marketed and sold in 15 countries with anticipated launches in 15 additional countries in 2017.

Source: Sanofi