Federal Circuit rules against Roche in Tamiflu case

The US Court of Appeals for the Federal Circuit has thrown out a lower court ruling that found Natco Pharma infringed a patent covering Roche’s flu drug Tamiflu (oseltamivir phosphate).

In a 2-1 decision, the appeals court found that the ‘483 patent, held by pharmaceutical company Gilead, is invalid for obviousness-style double patenting. The ruling gives Natco another opportunity to try to invalidate the patent so it can make a generic version of Tamiflu.

Gilead, along with Tamiflu marketers Roche and Genentech, sued India-based Natco after it filed an Abbreviated New Drug Application with the US Food and Drug Administration, seeking approval to make a product covered by the ‘483 patent.

During the case, filed at the US District Court for the District of New Jersey, Natco argued that the ‘483 patent was invalid for obviousness-type patenting over Gilead’s ‘375 patent, which like the ‘483 patent is directed at antiviral compounds and the method for their use.

Gilead said that even though the ‘483 patent expires 22 months after the ‘375 patent, as the ‘375 patent was issued after the ‘483 patent it could not serve as a reference for double patenting.

The district court agreed, and found that Natco infringed the Tamiflu patent.

Natco appealed against the ruling to the Federal Circuit, which on April 22 vacated the district court’s decision and remanded the case.

In a statement on its website, Natco said it was pleased with the Federal Circuit’s decision. According to IMS Health figures quoted in the statement, Tamiflu’s US sales reached about $495 million in the 12 months to September 2013.

A spokesperson for Genentech told LSIPR: “We are disappointed with the decision by the Court of Appeals for the Federal Circuit, but note that the appellate court did not opine on patent validity, and nor had the district court previously.”

She added: “We are studying the court’s decision, and considering various options and next steps.”