Glenmark Generics Ltd confirmed that Smithkline Beecham Corporation (Glaxosmithkline (GSK)) filed a patent infringement lawsuit on their US subsidiary, Glenmark Generics Inc, USA (Glenmark) in the US District Court for the District of Delaware in connection with the Abbreviated New Drug Application (ANDA) filing for atovaquone and proguanil hydrochloride 250mg/100mg tablets. GSK currently markets their product as Malarone in the United States and is indicated for the prevention and treatment of malaria. Total US sales as reported by IMS Health for the 12 month period ending June 2009 were approximately USD 53 million.

Glenmark believes it is the sole first to file applicant on this product. Glenmark had earlier filed its ANDA containing a paragraph IV certification for its generic version of atovaquone and proguanil hydrochloride tablets with the US Food & Drug Administration (FDA), and following receipt of the notice from the FDA that Glenmark's ANDA had been accepted for filing, notified the New Drug Application (NDA) holder and patent owner.

Smithkline Beecham Corporation's lawsuit is part of the patent challenge process under the Hatch-Waxman Act. Based on the information published by the FDA, Glenmark believes it may be the first applicant to have filed an ANDA for this product with a paragraph IV certification. In the event that Glenmark successfully challenges the patent, Glenmark will be entitled to a 180-day exclusivity period.

Glenmark's current portfolio consists of over 40 products authorized for distribution in the US marketplace. The company has 45 ANDA's pending for approval with the US FDA. With this filing, Glenmark has four sole first-to-file products currently under litigation under the Hatch-Waxman Act. The other three products are Zetia (ezetimibe), Tarka (trandolapril + verapamil) and Cutivate (fluticasone lotion). Pending successful patent challenges, Glenmark will be entitled to sole marketing exclusivity for the 180 day period.