Gilead Sciences, Inc. v. Natco Pharma Ltd.

January 07, 2013

GENERICally Speaking: A Hatch Waxman Litigation Bulletin

Case Name: Gilead Sciences, Inc. v. Natco Pharma Ltd., C. A. No. 11-CV-1455 (SDW), 2012 U.S. Dist. LEXIS 180717 (D.N.J. Dec. 21, 2012) (Wigenton, J.)

Drug Product and Patent(s)-in-Suit: Tamiflu® (oseltamivir phosphate); U.S. Pat. Nos. 5,763,483 (“the ’483 patent”), 5,952,375 (“the ’375 patent”), and 5,866,601 (“the ’601 patent”)

Nature of the Case and Issue(s) Presented: The ’483 patent issued from non-provisional application 08/774,345 (“the ’345 application”), which claimed the benefit of priority to provisional application 60/009,306 (“the ’306 application”), which was filed on December 29, 1995. The ’483 patent issued on June 9, 1998, which was before any other patent in the oseltamivir patent family issued. The ’375 and ’601 patents issued on September 14, 1999 from a series of CIP applications (collectively “the ’245 CIP family”). The earliest of the ’245 CIP family was application 08/395,245 (“the ’245 application”), which was filed on February 27, 1995. The ’375 and ’601 patents both claim priority to: (i) the ’245 application; (2) CIP application 08/476,946 (“the ’946 application”), which was filed on June 6, 1995, and issued as the ’601 patent; (3) and CIP application 08/580,567 (“the ’567 application”), which was filed on December 29, 1995. Application 08/606,624 (“the ’624 application”) was filed on February 26, 1996 as a CIP of the ’567 application. The ’624 application eventually issued as the ’375 patent. Only the ’375 and ’483 patents are relevant to this opinion.

In its counterclaims, Natco alleged that the claims of the ’483 patent are invalid due to obviousness-type double-patenting, and that the ’375 patent is the reference patent for its claim of double-patenting. Before the court was Gilead’s motion for summary judgment and Natco’s cross-motion for summary judgment. The narrow issue before the court was whether, between two closely related patents, the later-issued but earlier-expiring patent can be used as a reference patent to invalidate the earlier-issued and later-expiring patent. The court granted Gilead’s motion and denied Natco’s motion.

Why Gilead Prevailed: Natco argued that the ’375 patent could serve as a double-patenting reference against the ’483 patent. Based on the same reasoning, Natco also argued that the ’483 patent unlawfully extends the terms of the ’375 patent. Gilead contends that the ’375 patent cannot serve as a reference for double-patenting because it issued after the ’483 patent and terminates before the ’483 patent; thereby not making the ’483 patent an unlawful extension of the ’375 patent. Gilead cites two Delaware district court decisions holding that a later-issued but earlier-expiring patent cannot be used as an invalidating reference against an earlier-issued but later-expiring patent because logically a later-issued patent cannot be extended by a patent that was already in existence. Following the reasoning in those decisions, the court in the instant action found that the ’375 patent cannot serve as a reference patent as it issued after and terminates before the ’483 patent.

Natco further argued that Gilead obtained the ’483 patent in part because Gilead failed to disclose the ’624 application, which ultimately issued as the ’375 patent, to the USPTO. Natco highlights this nondisclosure because the ’567 application, the parent application to the ’624 application, contained a similar disclosure to the ’306 provisional application, which is the parent application for the ’483 patent. The court found, however, that Gilead notified the USPTO of the ’375 patent family of applications, including the ’567 application, which contained a similar disclosure to the ’306 provisional application. Therefore, the nondisclosure of the ’624 application, though it also contained a similar disclosure to the ’306 provisional application, is not detrimental to Gilead’s case because of Gilead’s disclosure of the ’567 application. Moreover, the lifespan of Gilead’s patents seem to be a result of changes in patent law, and not any gamesmanship from Gilead.




Oren D. Langer


Managing Partner, New York Office
Member of Executive Board

Ryan M. Schultz


Pronouns: he/him

Back to Top