Teva and Ranbaxy have failed in their bid to return a generic version of Pfizer’s blood pressure product Accupril (quinapril) to the US market.

The Court of Appeals for the Federal Circuit has now affirmed a lower court decision that imposed a preliminary injunction on sales of a generic quinapril product manufactured by Ranbaxy and Teva. Other non-infringing formulations remain on the US market, and led to an 84% slump in combined US sales of Accupril and combination product Accuretic (quinapril plus hydrochlorothiazide) to just $15 million in the third quarter of this year.

The case has been batted to and fro between the lower and appeals courts over the last few months. A preliminary injunction was served in March against Teva and Ranbaxy - which launched their version of the drug in December 2004 - after a US district court held that Pfizer was likely to prevail in an ongoing patent infringement lawsuit. However, the appeals court sent the case back to a lower court for further review in September.

Pfizer's patent infringement action against Ranbaxy and Teva remains pending in district court in New Jersey, where the company is seeking damages resulting from lost sales.