Lipitor Patent Battle: Pfizer Plots New Course In Suit With Apotex

Two years ago, Pfizer inked a settlement with Ranbaxy, the first ANDA filer for generic Lipitor, that it believed would prevent generic competition in the U.S. until November 2011.

But Apotex sought to trigger Ranbaxy's 180-day exclusivity for generic atorvastatin ahead of this schedule by seeking a declaratory judgment that other Lipitor patents are invalid or not infringed. A recent court ruling in Apotex's favor has prompted Pfizer to come up with a new legal strategy to ward off competition on its blockbuster, which had sales of $11.4 billion last year.

The battle began when Apotex filed an ANDA for atorvastatin in 2008 and Pfizer sued it for infringement of one patent, which was later reissued as a different patent. Apotex then filed counterclaims against Pfizer requesting a declaratory judgment that these patents and three other unasserted Lipitor patents were invalid and not infringed.

Pfizer filed a motion in the U.S. District Court for the Northern District of Illinois to dismiss Apotex's counterclaims. The court denied its request in a June 30 order, finding that Apotex has alleged an injury that is sufficiently imminent - a delay in marketing its product until at least November 2011 if there is no court ruling on the unasserted patents.

The court said this delay is traceable to Pfizer as a result of its listing of the patents in FDA's Orange Book and the Ranbaxy settlement agreement.

Pfizer Files Suit Over Different Patent

Pfizer is seeking to get around this finding. In a July 21 filing, Pfizer said that in response to the court's order it had granted a covenant not to sue Apotex on two of the unasserted patents - the formulation patents. And at the same time it filed a new suit against Apotex claiming infringement of the '156 patent, which expires in January 2017.

As a result of these actions Pfizer said Apotex cannot overcome Ranbaxy's 180-day exclusivity rights unless and until it prevails on the '156 patent.

Pfizer said the actual cause of Apotex's concerns is Ranbaxy's own failure to get FDA approval of its ANDA, "not the speculation that Pfizer's formulation patents or the Ranbaxy settlement may create some sort of block to FDA approval while the '156 patent is still being litigated."

Pfizer Cites Ranbaxy GMP Problems

Pfizer said Ranbaxy has been unable to get FDA approval because of its own actions. It included exhibits of FDA warning letters issued in 2008 and 2009 citing current good manufacturing violations at Ranbaxy facilities in Dewas, India and Gloversville, N.Y. It also included a February 2009 FDA release stating Ranbaxy's Paonta Sahib plant in India had falsified data and test results in approved and pending applications. Early this year, FDA told the company its corrective actions were inadequate (¹ (Also see "Corrective Actions "Inadequate," FDA Warns Ranbaxy" - Pink Sheet, 5 Feb, 2010.)).

"Once Ranbaxy solves its issues with FDA, the FDA will approve Ranbaxy's ANDA allowing Ranbaxy to market and Apotex will be free to go to market after the 180-day period authorized by Congress," Pfizer stated in the filing. "The timing of the resolution of those issues is wholly dependent on the FDA and Ranbaxy. This is the only possible imminent harm Apotex is facing."

Pfizer's settlement with Ranbaxy involved the basic compound patent, which expired in March 2010, and the enantiomer patent, which expires in June 2011 (² (Also see "Pfizer Stalls Generic Lipitor With Ranbaxy Deal" - Pink Sheet, 18 Jun, 2008.)). Pfizer has also sued Mylan, Dr. Reddy's and Schwarz Pharma's subsidiary KUDCO for infringement of the '156 patent.

Aaron Barkhoff, an attorney at McDonnell Boehnen Hulbert & Berghoff LLP, wrote in a blog post that the longer the case lasts, "the less likely Apotex is to obtain the declaratory judgment it seeks, get the judgment affirmed by the Federal Circuit and trigger Ranbaxy's exclusivity." He said Pfizer might simply run out the clock.

By filing a new suit against Apotex over the '156 patent Pfizer has extended the legal battle. In a status report Pfizer filed with the court on July 26 it proposes a schedule for the litigation with motions extending to May 21, 2012.

- Brenda Sandburg ( ³ [email protected] )