MUMBAI, April 10 (Reuters) - India's Natco Pharma Ltd has formally asked the Indian patent office to deny U.S. drugmaker Gilead Sciences Inc's breakthrough hepatitis C drug Sovaldi a patent in India, a source with direct knowledge of the matter said.
If successful, the move could clear the way for the Indian company to launch a generic version of the drug.
Natco has filed a so-called "pre-grant opposition" with India's Controller General of Patents, Designs & Trademarks, said the source, who declined to be named because the information was not public yet.
Reuters could not immediately obtain a copy of the filing.
Natco Chief Executive Rajeev Nannapaneni declined to comment. Officials at the Indian patent department in Mumbai were not immediately available for comment.
India's patent laws allow a third party to dispute the validity of a pending patent application. Natco has opposed the patent on the grounds that Sovaldi is not "inventive" enough, the source said.
Foster City, California,-based Gilead aims to license Sovaldi to three or four Indian generic manufacturers to allow sale of the medicine at lower prices in some 60 developing nations including India. (Reporting by Zeba Siddiqui in MUMBAI; Editing by Tony Munroe)