Generic Lovenox Battle Heats Up With Amphastar’s ANDA Approval
Executive Summary
Momenta Pharmaceuticals and Sandoz have enjoyed approximately 14 months of de facto generic exclusivity on Sanofi’s anticoagulant Lovenox (enoxaparin), but faced with the imminent threat of competition they are trying to maintain their hold on the market through patent litigation.
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Momenta Pharmaceuticals and Sandoz have enjoyed approximately 14 months of de facto generic exclusivity on Sanofi’s anticoagulant Lovenox (enoxaparin), but faced with the imminent threat of competition they are trying to maintain their hold on the market through patent litigation. Momenta/Sandoz sued Amphastar Pharmaceuticals on Sept. 21, alleging infringement of two enoxaparin patents held by Momenta. The lawsuit was filed two days after Amphastar’s enoxaparin ANDA was approved, positioning Amphastar and its marketing partner, Watson Pharmaceuticals, to be the second marketed generic of Sanofi’s low molecular weight heparin. Watson is also named as a defendant in Momenta’s lawsuit, as is International Medication Systems, an Amphastar subsidiary.
The complaint filed in the U.S. District Court for the District of Massachusetts extends the line of lawsuits filed and pending since the first Lovenox generic was approved. One of those actions, brought by Amphastar against FDA last year, is now history, having been voluntarily dismissed following the company’s ANDA approval. Eyeing The End Of De Facto Exclusivity Momenta and Sandoz won the race to market for generic enoxaparin when their ANDA was approved in July 2010. Although Lovenox is not a biologic, it is a complex compound that raises problematic issues with regard to characterization. FDA’s review of enoxaparin ANDAs has been closely scrutinized for clues as to how the agency will evaluate biosimilar product applications (Also see "FDA Approves Momenta/Sandoz' Lovenox Generic Without Need For Clinical Studies" - Pink Sheet, 26 Jul, 2010.). Sanofi quickly sued the agency, challenging the ANDA approval. Although a federal court denied Sanofi’s request for a preliminary injunction overturning the approval, the lawsuit is pending (Also see "Court Backs FDA Rationale For Approving Generic Lovenox" - Pink Sheet, 30 Aug, 2010.). Momenta/Sandoz became the first generic approved even though their ANDA was submitted behind Amphastar and Teva Pharmaceutical Industries. Both companies filed their applications in 2003, ahead of the 2005 filing by Momenta/Sandoz. By the time Momenta/Sandoz won approval there was no 180-day generic marketing exclusivity available. Waxman-Hatch exclusivity was triggered in October 2008 by a federal appeals court ruling finding two Lovenox patents unenforceable. Nevertheless, since their July 2010 launch Momenta/Sandoz have enjoyed healthy sales thanks to de facto exclusivity that comes from being the only approved generic. Sandoz has described enoxaparin as one of the most successful generic launches in the U.S. In the second quarter of 2011, the Novartis subsidiary reported enoxaparin sales of $284 million. Momenta/Sandoz now face an immediate competitive threat from Amphastar and Watson, which expect to launch in the fourth quarter. 2011: A Year Of Big Launches For Watson Amphastar originally signed Andrx Corp. as its marketing partner for generic enoxaparin in 2005. Watson came into the picture in 2006 when it acquired Andrx for $1.9 billion. Watson is also preparing for the fourth quarter launch of an even more high-profile product than Lovenox. The company is set to introduce an authorized generic of Pfizer’s Lipitor (atorvastatin) in November and could find itself the only generic on the market (Also see "The Last Days Of Lipitor: Morass Of Regulatory, Legal Issues Could Mean Few Early Generics" - Pink Sheet, 14 Feb, 2011.). Under the terms of their distribution deal, Watson will market Amphastar’s generic to the U.S. retail pharmacy channel, which accounts for approximately 40% of enoxaparin sales, Amphastar told “The Pink Sheet.” Amphastar will receive 50%-55% of Watson’s gross profits on product sales depending upon the number of competitors in the market. Amphastar will distribute its product to hospitals through wholesalers and group purchasing organizations. One Lawsuit Is Filed … However, Amphastar and Watson now face a potential roadblock in the form of a patent infringement lawsuit filed by Momenta and Sandoz. The plaintiffs allege that Amphastar/Watson have manufactured, or are in the process of manufacturing, commercial quantities of enoxaparin sodium using the methods claimed in two patents held by Momenta. Those patents, Nos. 7,575,886 and 7,790,466, claim methods of producing enoxaparin having specified quality attributes. Momenta and Sandoz filed a similar patent infringement lawsuit against Teva in December. That complaint cited statements by Teva executives suggesting the company was manufacturing product for launch and expecting ANDA approval soon. Momenta told “The Pink Sheet” it did not have a legal basis to sue Amphastar and Watson at the time it sued Teva.
The lawsuit seeks a court order determining that Amphastar/Watson have infringed Momenta’s patents, as well as preliminary and permanent injunctive relief. The filing does not seek a temporary restraining order, and Momenta said it could not comment on whether it would seek a TRO in the future. Amphastar and Watson said they will vigorously defend the lawsuit. Watson said that pursuant to the terms of the distribution agreement, it believes it will be fully indemnified by Amphastar for all costs, expenses and damages, if any, incurred in connection with the lawsuit. “It is ridiculous that the third filer has the nerve to sue the first filer of an ANDA, especially when Amphastar was the one to invalidate the innovator's patent for the same ANDA,” Amphastar said. The lawsuit is contrary to fact, science and public policy, the company asserted, adding that Momenta is acting “like a patent troll.” … And Another Is Dismissed Ironically, Amphastar was named as a defendant in the patent litigation one day after the company voluntarily dismissed its own legal action against FDA. Amphastar originally sued in October 2010, challenging the agency’s detention of heparin raw ingredient shipments (Also see "Amphastar Lawsuit Over Heparin Shipments Suggests Lovenox ANDA Approval May Be Far Off" - Pink Sheet, 1 Nov, 2010.). Even though FDA subsequently released the material at issue, Amphastar filed an amended complaint in December, requesting a court ruling that the agency acted unlawfully by allegedly giving preferential treatment to Momenta/Sandoz’ ANDA and directing FDA to approve Amphastar’s product (Also see "Amphastar Seeks Court Order Requiring FDA To Approve Its Enoxaparin ANDA" - Pink Sheet, 3 Jan, 2011.). Amphastar dismissed the action on Sept. 20. “The company deemed the lawsuit unnecessary now that our generic for enoxaparin was approved,” Amphastar said. Meanwhile, Teva remains enmeshed in patent litigation with Momenta/Sandoz, and its ANDA is still awaiting approval. The company reported in January that it had received a “minor deficiency letter” from FDA requesting responses to a short list of questions (Also see "New Delay For Teva's Generic Lovenox Bodes Well For Sandoz/Momenta Sales" - Pink Sheet, 25 Jan, 2011.). By Sue Sutter |