Pfizer says it is disappointed with a UK Court of Appeal ruling backing an earlier judgement that its patent protecting pregabalin for pain has not been infringed by Actavis.

The drug giant's original patent for pregabalin (sold as Lyrica) as a treatment for epilepsy expired in 2014, paving the way for Actavis and others to launch cheaper generic formulations for the condition and generalised anxiety disorder.

However, Pfizer also secured a second-use patent protecting pregabalin as a treatment for pain until July 2017. In the complex and closely-watched legal case, the firm argued that Actavis' generic alternative, and others, would inevitably also be used to treat pain despite targeting non-protected indications, and thus infringe its patent.

However, the Court of Appeal has now affirmed the High Court's decision that the patent covering pregabalin for pain is not infringed by Actavis, and also that patent claims directed generally to pain and neuropathic pain are invalid.

It did, however, affirm the High Court's decision in upholding as valid Pfizer's patent claims directed to certain types of pain, including acute herpetic pain, postherpetic pain and causalgia pain, the firm noted.

Pfizer said it "maintains its strong belief in the validity and importance of the second medical use patent for the use of Lyrica in pain," and stressed that it now intends to seek permission to appeal the decision to the Supreme Court.