Pfizer Sues Ranbaxy To Block Generic Caduet Until 2016

Pfizer Inc. lodged a declaratory judgment suit on Monday claiming that Ranbaxy's proposed generic would infringe two patents related to atorvastatin, in a move that could stop Ranbaxy Laboratories Ltd. from marketing a generic version of the Caduet until 2016.

Pfizer filed its complaint in the U.S. District Court for the District of Delaware, seeking a judgment that Ranbaxy's copycat Caduet would infringe two patents Pfizer says are valid through July 16, 2016. The suit seeks injunctive relief barring Ranbaxy from making, selling or importing its generic until those patents expire.

Pfizer's suit centers on U.S. Patent Numbers 6,087,511 and 6,274,740 — which issued in 2000 and 2001, respectively. Both patents cover methods of making amorphous atorvastatin, Pfizer's complaint said.

The active ingredients of Caduet, which is a combination of the Pfizer drugs Lipitor and Norvasc, are atorvastatin calcium and amlopdipine besylate.

The atorvastatin calcium and amlodipine besylate product contemplated in Ranbaxy's abbreviated new drug application is made by a process that would infringe the '511 and '740 patents, and Ranbaxy's importation and/or future sales of the ANDA product will also infringe the patents at issue, according to Pfizer.

Ranbaxy is looking to market its generic Caduet as soon as it can get FDA approval, Pfizer said.
Ranbaxy notified Pfizer that it had filed an ANDA seeking approval for generic Caduet in January 2007, which led Pfizer to sue Ranbaxy in Delaware in March of that year.

In that suit, Pfizer asserted U.S. Patent Numbers 4,681,893 and 6,455,574. Ranbaxy also brought U.S. Patent Number 5,273,995 into the mix by filing counterclaims alleging that the '995 patent in invalid and unenforceable or not infringed.

In November 2007, the district court in Delaware granted Pfizer's bid for a judgment that Ranbaxy had infringed the '893 patent.

The complaint Pfizer filed Monday notes that the New York-based pharmaceutical giant already won a judgment that enjoined the effective date of approval of Ranbaxy's ANDA Number 78-747 — which seeks the U.S. Food and Drug Administration's permission to make and sell generic Caduet — until the expiration of the '893 patent.

Adding on six months of pediatric exclusivity, to which Pfizer claims to be entitled, extends the exclusivity afforded by the '893 patent through March 24, 2010, the plaintiff claims.