Pfizer (NYSE:PFE) fell in morning trade on Friday, a day after the world’s largest U.S. drugmaker suffered a major setback in the UK.
The High Court in London ruled that claims of patent protection for the use of its US$5bn-a-year drug Lyrica as a pain treatment were invalid.
Shares were down 0.6% at $32.42 at 9:48 a.m. in New York.
Lyrica was originally developed for epilepsy, but further research showed it could also help patients suffering from neuropathic pain and most prescriptions are now written for pain.
While the original patent on Lyrica expired last year, Pfizer won a secondary patent covering pain, valid until July 2017, and the New York-based company had been fighting to protect that lucrative section of the market.
Pfizer said in a statement that it maintained its strong belief in the validity and importance of the second medical use patent for pain and it intended to appeal the ruling.
The case is specific to Britain and has no direct implications for other markets, where Pfizer also has secondary patent protection for Lyrica in neuropathic pain.