Hyderabad-based Natco markets Copaxone (Glatiramer Acetate) -- used in the treatment of relapsing-remitting multiple sclerosis -- in the US market.
The drug's patent to Teva is set to expire in May. Buoyed by the news, shares of Natco Pharma Ltd rose over 6 per cent at Rs. 756.50 on BSE in the afternoon trade.
Natco said in a statement: "The United States Patent and Trademark Office (the "PTO") issued a final office action rejecting Teva's application seeking a reissue of US Patent No. 5,800,808 (the "'808 Patent"), which was found to be invalid by the Court of Appeals for the Federal Circuit in July 2013."
It added: "The final rejection issued today finds the first claim of the re-issue application, which is identical to the only claim in the '808 Patent, to be indefinite and both claims of the reissue application to be unpatentable based on obvious-type double patenting.
In its ruling, the PTO refused to extend patent protection on Copaxone(R) past the patents that will expire in May 2014.
"Recently, the US Supreme Court agreed to hear an appeal filed by Teva on Copaxone generic drug patent litigation case also involving Natco Pharma.
Last year, US Court of Appeals for the Federal Circuit reversed a district court's earlier finding related to Teva's US Patent for the drug.
Natco has marketing tie up with Mylan Inc to market this drug in USA.
"Natco confirms the final decision as to when and whether and pricing of generic Copaxone is launched in the US rests with its partner Mylan," Natco said in a statement yesterday.
According to Teva's annual report, the drug product clocked revenues globally of over $4.2 billion during 2013.