Pfizer could face £502M bill if it comes up short in U.K. patent appeal for Lyrica

Pfizer has been fighting to defend patent protections for its big-selling Lyrica in the U.K., but if those efforts are unsuccessful, the company could be on the hook for £502 million ($700 million) in government spending on the branded med, according to a new study. 

After a court invalidated a key patent in 2015, Pfizer took its appeals all the way to the Supreme Court. If the company comes up short in that effort—hearings for which took place earlier this month—the National Health Service could work to claw back more than half a billion pounds, researchers wrote in a study published in BioRxiv. 

The government healthcare system spent £502 million more on the drug between September 2015 and July 2017 than it would have if Pfizer hadn't challenged the patent ruling, according to the researchers. They concluded the "NHS can seek reimbursement of excess pregabalin prescribing costs," potentially up to that amount, if the Supreme Court rules against Pfizer. 

A Pfizer spokesperson said the company strongly believes "in the validity and importance of the second medical use patent for the use of Lyrica in pain," noting that the drugmaker had Supreme Court permission to appeal an earlier decision.

"We await the decision from the Supreme Court and are unable to provide further comment until after this is received," he added.

Lyrica's original patent ran out in 2014 in the U.K., but at the time Pfizer had a follow-up patent protecting its use as a pain med. That IP wasn't set to expire until July 2017. And the company aggressively defended that patent: It sent a letter to providers warning them of legal action if they prescribed Lyrica generics to treat pain; NHS England also sent out guidance to warn against using Lyrica copies to treat pain.

But in September 2015, a court ruled that the 2017 pain patent was invalid. The judge scolded the company for "groundless" threats to doctors. Since then, Pfizer has appealed multiple times. Now, the researchers conclude the government should attempt to recoup overspending if that appeal is unsuccessful.

The company's spokesperson said that "during the life of the patent, Pfizer has always made clear that it was not seeking to prevent the use of generic pregabalin to treat generalised anxiety disorder or epilepsy, which are not patent protected."

RELATED: Don't use generic Lyrica for pain, Pfizer warns U.K. providers

Pfizer is coming up to the end of its Lyrica patent protections in the U.S. as well. The megablockbuster is set to lose exclusivity in December unless Pfizer can win a six-month pediatric exclusivity extension from the FDA. The company is already suffering from Viagra competition in the U.S. market after Teva's generic launch in December.

Editor's note: This story was updated with a statement from Pfizer.