India’s Sun Pharma is planning to make generic version of the painkiller drug tramadol extended release for US market, raising possibility of encountering patent infringement lawsuit from Ryzolt’s developer Lobopharm and its marketing partner Purdue.
Sun Pharma’s proposed tramadol extended release pills are the generic substitute for Canadian drugmaker Labopharm Inc’s painkiller Ryzolt.
Sun Pharma applied for an Abbreviated New Drug Application with the U.S. Food and Drug Administration (ANDA) recently for approval to market 100, 200 and 300 mg generic versions of Ryzolt (tramadol hydrochloride extended-release).
Tramadol hydrochloride extended-release pills were launched in the United States by Labopharm in the brand name Ryzolt along with marketing partner Purdue earlier this year.
Under the Drug Price Competition and Patent Term Restoration Act (known as the Hatch-Waxman Act), Ryzolt has a new dosage form market exclusivity period that prevents final approval of Sun’s ANDA until the exclusivity period expires on December 31, 2011.
Lobopharm currently owns one patent (U.S. Patent No. 6,607,748) on tramadol hydrochloride extended-release which will expire only in 2020.
Tramadol hydrochloride extended-release’s other patents are owned by Purdue Pharma. Several of such patents including patent Nos. 5,591,452, 6,254,887 and 6,607,748. U.S. Patent Nos. 5,591,452 and 6,254,887,held by Purdue on tramadol hydrochloride extended-release are set to expire expire in May 2014.
Sun’s ANDA includes a paragraph IV certification to obtain approval to manufacture, use, or sell its generic versions before the expiration of the above-mentioned patents.
Labopharm is currently reviewing the notice letter with Purdue to determine the next steps in this matter, Lobopharm said in an official release.
In August, a court in Delaware ruled in favor of U.S.-based generic drugmaker Par Pharmaceuticals Inc in a patent-infringement case against Purdue Pharma related to tramadol.
Purdue Pharma Products L.P. initiated a patent-infringement litigation against Par Pharmaceutical Companies, Inc. relating to Ultram ER (tramadol hydrochloride extended-release tablets).
The patents-in-suit are owned by Purdue and were licensed to Ortho-McNeil, Inc., the marketer of Ultram ER.
The court judged in favor of Purdue and against Par on the issue of infringement and rejected Par’s claim that the patents were unenforceable for inequitable conduct.
This judgment could permit Par to market its generic formulation of Ultram ER in the U.S., should it receive final regulatory approval from the U.S. Food and Drug Administration.
Although Labopharm is not a party to this action, if Par was to launch its generic formulation of Ultram ER, it could impact U.S. sales of Labopharm’s own once-daily tramadol product, Ryzolt, which is marketed in the U.S. by Purdue.
Ultram ER is not A/B rated to Ryzolt, meaning it cannot be substituted for Ryzolt at the pharmacy.
Based in Canada, Labopharm focuses its research for optimizing the performance of existing small molecule drugs using its proprietary controlled-release technologies. Once-daily formulation of tramadol, which is now available in 17 countries around the world, including the U.S., Canada, major European markets and Australia, is Lobopharm’s lead product.
once-daily formulation of the analgesic tramadol is indicated for the treatment of moderate to severe pain.
The global market for tramadol products are achieving a compounded annual growth rate of 13% over the last five years ended 2008. The market potential for our once-daily tramadol product, however, goes beyond that of the current tramadol market.
Tramadol has the ability to compete in the broader market that addresses patients using combination opioids or tramadol/combination products, or those for whom NSAIDs and COX-2s are no longer appropriate – a group for whom 190 million prescriptions were written in the U.S. alone in 2008.
Lobopharm has another novel formulation of trazodone for the treatment of major depressive disorder, is under regulatory review in the U.S. by the FDA. Lobopharma also has a pipeline of follow-on products in both pre-clinical and clinical development.