Generics circle as Virginia court invalidates Celebrex patent
The US District Court for the Eastern District of Virginia has invalidated one of Pfizer’s patents covering blockbuster arthritis drug Celebrex.
Reissue patent RE44,048, which is held by Pfizer subsidiary G.D. Searle, covers methods of treating osteoarthritis and other conditions with Celebrex’s active ingredient celecoxib.
The ruling makes Pfizer’s fourth biggest selling drug, which made nearly $3 billion in worldwide sales last year, vulnerable to generic competition much earlier than the ‘048 expiry date of December 2, 2015 (including six months of paediatric exclusivity).
Pfizer said it disagreed with the ruling and “will pursue all remedies, including an immediate appeal of the court’s decision”.
Actavis and Mylan said that they expect to launch generic versions of Celebrex after the remaining three Celebrex patents expire in May.
Pfizer brought the action against generic drugmakers Teva, Mylan, Watson Laboratories (now Actavis), Lupin and Apotex on March 5, 2013, the day the US Patent and Trademark Office (USPTO) issued the ‘048 patent.
The generics had filed Abbreviated New Drug Applications (ANDAs) with the US Food and Drug Administration, seeking approval to market a generic version of Celebrex after Pfizer’s basic compound patent covering the drug expires, but before the expiry of the ‘048 patent.
In 2008, the US Appeals Court for the Federal Circuit invalidated the original method of use patent, 5,760,068, after a challenge from Teva. After the ruling, Pfizer worked with the USPTO to correct “prosecution errors”, which eventually led to the issue of the ‘048 as a valid reissue of ‘068.
