The US District Court of Delaware has ruled in favour of Cephalon over patent infringement, relating to Watson Pharmaceutical’s generic version of Fentora.

Cephalon originally began selling the cancer-related pain medication in 2006 and has sought to block any generic competition after it claimed worldwide sales of $181.6m in 2010.

The case follows a 2009 settlement with Teva Pharmaceutical, wherein the Israel-based pharmaceutical major agreed not to market a generic version until 2018.

According to the US-based company, patents covering Fentora do not expire until 2019 and Cephalon has since filed patent-infringement suits against Watson and at least two other companies who have challenged the validity of the patents.