The Supreme Court decision is a blow for the U.S. drugmaker — which had sought to affirm a secondary medical use patent for the product — and a win for generic drug companies Actavis, now renamed Allergan, and Mylan.
Lyrica, known generically as pregabalin, was originally developed for epilepsy but further research showed it could also help patients suffering from neuropathic pain, which soon became its main market.
In a bid to protect this lucrative section of the market, Pfizer secured a secondary patent, valid beyond the life of the original one.
The Supreme Court, however, ruled that the secondary patent claims relevant to neuropathic pain were invalid.
For Pfizer, the legal fight had become a point of principle, following years of battles in lower courts, since its key secondary pain patent has now expired in Europe.