Pozen Migraine Drug Patent Win Upheld By Federal Circuit

San Diego – The Federal Circuit on Friday shot down several generic drug makers’ appeal of an injunction against selling their generic versions of Pozen Inc.’s patented migraine medicine Treximet.

Par Pharmaceutical Inc., Alphapharm Pty Ltd. and Dr. Reddy’s Laboratories Inc. had appealed a Texas federal judge’s ruling that the asserted claims of Pozen’s U.S. Patent Numbers 6,060,499, 6,586,458 and 7,332,183 were valid and infringed by Par and Dr. Reddy’s’ Abbreviated New Drug Application filings with the U.S. Food and Drug Administration.

The district court did not err in rejecting the generics makers’ claims that the patents are invalid as obvious, nor did the court err in its infringement finding, the Federal Circuit ruled in affirming the Texas court’s decision and related injunction.

Pozen developed a method for treating migraines by combining two drugs, sumatriptan and naproxen, in a single tablet, which it markets as Treximet in conjunction with GlaxoSmithKline. Sumatriptan was developed in the late 1980s and is widely accepted as an effective medicine for migraines, but does not prevent the reoccurrence of migraine symptoms. Naproxen, meanwhile, is a well known nonsteriodal anti-inflammatory drug.

On appeal, the generics makers challenged the validity of the ‘499 and ‘458 patents in light of four prior art references. They also challenged the validity of the ‘183 patent in light of the ‘499 patent and prior art.

The generics companies asked the Federal Circuit to hold the ‘499 patent invalid for lack of written description, and challenged the district court’s determination that the ‘183 patent was infringed.

“Appellants failed to rebut the presumption of validity of issued patents,” the Federal Circuit ruled. “Additionally, the appellants provided no basis for unsettling the district court’s finding on infringement.”

The appeals court accordingly affirmed the district court’s injunction barring the three generics makers from making, using, importing, selling or offering to sell their generic Treximet products, or inducing others to do so, until the expiration of the three Pozen patents.

Circuit Judge Raymond Clevenger dissented in part from the Federal Circuit’s majority opinion, saying the district court erred in finding infringement of one claim of the ‘183 patent under the doctrine of equivalents.