The US Patent and Trademark Office (PTO) has rejected Israel-based drug-maker Teva Pharmaceuticals’ request for an extension of patent protection on Copaxone, which will expire next month.

“The decision of the PTO came after a review of an application filed by Teva seeking reissue of patent, which was found to be invalid by the Court of Appeals for the Federal Circuit in July 2013,” Natco Pharma said in a release.

Hyderabad-based Natco, which seeks to market the generic version of Copaxone, is currently engaged in a patent row with Teva. The PTO order had an immediate impact on Natco’s scrip, which rose 5.06 per cent on BSE to ₹748.95 on Friday.

Copaxone (Glatiramer Acetate) is used in the treatment of multiple sclerosis and had registered a revenue of $4.2 billion (₹25,200 crore today) in the US in 2013.

“Natco is pleased that the PTO has rejected the reissue application, confirming the indefiniteness for the second time and consistent with the Federal Circuit's decision, and that the PTO continues to find all claims to be unpatentable,” it said.

The 2003 decision of the US court to declare invalid Teva’s Copaxone patents made generic entry possible. Remaining patents on Copaxone are set to expire in May. This cleared the road for Natco, in partnership with Mylan and Momenta Pharmaceuticals, to move in.

But early this week, the US Supreme Court had agreed to hear the case again in response to a petition by Teva. While the latest decision of the PTO is a positive sign for Natco, which is gearing up to launch the generic version of Copaxone, uncertainty still remains as it depends on the outcome of US Supreme Court hearing on the case.

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