India's Natco wins again with U.S. challenge to Tamiflu generic

Natco Pharma won another battle in its quest to knock down patent barriers to its generic drugs, this time for a version of the Gilead Sciences' ($GILD) influenza treatment Tamiflu (oseltamivir). The U.S. Supreme Court refused to accept Gilead's appeal of a lower-court decision in favor of Natco.

Natco teamed up with Alvogen in the United States to market the generic one year ago after the FDA gave it a tentative approval. Gilead, which had licensed the drug to Roche ($RHHBY) for the U.S. market, sued to block the Natco generic, saying it would violate the Gilead patent for the drug still in force in the United States.

Natco and Alvogen responded that Gilead was asserting protection under a more recent patent that constituted double-patenting, and not that the original one that had expired. The court agreed with Gilead and Natco appealed the decision.

A two-judge panel of an Appeals Court reversed the lower court's decision. The two judges said the two patents were not part of the same family and that Gilead had "crafted a separate 'chain' of applications." Gilead appealed that ruling to the highest court, which declined to accept it, leaving the Appeals Court decision in place.

Natco is not free yet to market the generic. The case now returns to the original District Court to reconsider the case in light of the Appeals Court decision. As it stands, the Gilead patent it is attempting to assert does not expire until Dec. 27, 2016.

In the past few years Natco has won a series of patent challenges in India, including against Bayer's Nexavar and Glivec/Gleevec from Novartis ($NVS). It recently began selling licensed copied of Gilead's hepatitis C treatments in Nepal, less than a week after inking a license deal making it the first to do so.

- here's the Natco release
- and the U.S. Supreme Court refusal and Appeals Court ruling

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