Pfizer Inc. announced that the United States District Court for the District of Delaware ruled that Pfizer’s patent covering a method for using sirolimus, the active ingredient in Rapamune, for the inhibition of organ transplant rejection is valid and infringed. The company brought a patent infringement action in April 2010 against the generic company Watson Laboratories, Inc—Florida (now known as Actavis) and three other Watson entities after Watson applied to the FDA to market a generic version of Rapamune. The Court’s decision prevents Watson from marketing its generic version of Rapamune in the US before Pfizer’s patent expires, pending a possible appeal by Watson.

The patent at issue in the lawsuit is US Patent No. 5,100,899, which including paediatric exclusivity, expires January 7, 2014. In response to the decision, Amy Schulman, executive vice president and general counsel for Pfizer, said, “We are pleased with the Court’s decision, recognizing the validity of our patent."

In the United States, Rapamune is indicated for the prevention of organ transplant rejection in kidney transplant patients aged 13 years and older.

Rapamune (sirolimus) is indicated for the prevention of organ rejection in kidney transplant patients aged 13 years or older. Blood levels of sirolimus should be checked in all patients taking Rapamune.