Pfizer sues cobalt for filing atorvastatin sodium NDA

Earlier in the day i have posted the news that cobalt was sued by Pfizer for filing the Atorvastatin sodium NDA. Please find below the complete details of this news

Pfizer Inc. is alleging that when Cobalt Pharmaceuticals Inc. filed a New Drug Application for a product whose active ingredient would be atorvastatin sodium, the Canadian generics outfit infringed a patent covering the blockbuster cholesterol drug Litpitor.Pfizer and a group of subsidiaries including Warner Lambert Co. filed a suit against Cobalt on Friday in federal court in Boston. The suit accused Cobalt of infringing a patent owned by Warner Lambert.The same plaintiffs filed a suit against Cobalt in Delaware on Thursday. That suit accused Cobalt of infringing the same patent and referenced the same NDA. A Pfizer representative would not comment Monday on why the infringement claims were filed in different jurisdictions.At issue is U.S. Patent Number 5,273,995, which was issued in 1993, is owned by Warner Lambert and covers Lipitor, the complaint said. Lipitor, a formulation of atorvastatin calcium, brought in $3.2 billion in worldwide revenues for Pfizer in the third quarter of 2007, according to a Pfizer press release dated Oct. 18.Pfizer received a letter from Cobalt, dated Oct. 24, 2007, alerting Pfizer that Cobalt had filed NDA No. 22-245 asking for the U.S. Food and Drug Administration's approval to make and sell a product containing atorvastatin sodium as its active ingredient before the expiration of the '995 patent, the complaint said.The expiration date on the '955 patent in Dec. 28, 2010, but Lipitor was granted an extension of exclusivity through June 28, 2011, Pfizer said.Cobalt infringed the patent by submitting its NDA, Pfizer claimedClaim 6 of the '995 patent was declared invalid by the U.S. Court of Appeals for the Federal Circuit in August 2006, but the complaint does not seek relief based on that claim, Pfizer said.Indian generic drug maker Ranbaxy Laboratories Ltd. brought the appeal that led to claim 6's invalidation, following a December 2005 defeat in federal court in Delaware. Pfizer said it plans to rectify the flaw in the ‘995 patent through the U.S. Patent and Trademark Office.The Federal Circuit's August ruling upheld U.S. Patent Number 4,681,893, which covers atorvastatin, Lipitor’s active ingredient.The Federal Circuit deemed claim 6 of U.S. Patent Number 5,273,995 invalid because it failed to comply with the requirements of 35 U.S.C. Section 112, paragraph 4, which deals with dependent claims.That paragraph specifically says that a dependent claim shall “specify a further limitation of the subject matter claimed.”The Federal Circuit referenced the district court’s reluctance to declare the ‘995 patent — which deals with the calcium salt of atorvastatin — invalid. Although the lower court recognized that “there may be a technical problem in the drafting of claim 6,” it didn’t see that flaw as adequate grounds for a declaration of invalidity.But the Federal Circuit disagreed, swayed by Ranbaxy’s argument that the claim failed to properly specify limits to the subject matter it refers to.Pfizer wants a judgment from the Boston court holding that the effective date of any FDA approval for NDA 22-245 can't be earlier than June 28, 2011; a permanent injunction barring from making, selling or importing the product contemplated in the NDA; and attorneys' fees and costs.A Cobalt representative could not be immediately reached to discuss the lawsuits.In the Boston action, Pfizer is represented by Cesari & McKenna LLP. Connolly Bove Lodge & Hutz LLP is of counsel.The case is Pfizer et al. v. Cobalt Pharmaceuticals Inc., case number 07-12257 in the U.S. District Court for the District of Massachusetts.The Delware case is Pfizer Inc. et al v. Cobalt Pharmaceuticals, Inc. case number 07-790 in the U.S. District Court for the District of Delaware.