Chinta & Fratangelo LLP

Gilead v. Natco – Gilead’s patent invalid for obviousness-type double patenting

Contact the author: Andrew Berks
Gilead Sciences, Inc. v. Natco Pharma Ltd., No. 2013-1418 (Fed. Cir. 4/22/2014)

Gilead owns U.S. Patents 5,763,483 and 5,952,375, directed to antiviral compounds and their methods of use. The two patents have the same inventorship and are said to have similar subject matter, but they do not claim priority to a common patent application. The ‘375 patent was filed earlier and issued later than the ‘483 patent. Because of the difference in the earliest file dates, the ‘483 patent expires 22 months later than the ‘383 patent. The filing, issue, and expiration dates are mapped as:


Natco filed an ANDA for a drug covered by the ‘483 patent, and Natco’s only defense when sued for infringement of the ‘483 patent was obviousness-type double patenting, i.e., the assertion that the ‘483 patent was an obvious variation over the ‘375 patent that improperly sought to extend the right to exclude past the expiration of the ‘375 patent.

The district court held for Gilead, concluding that a later-issued but earlier-expiring patent cannot serve as a double patenting reference to an earlier-issued but later-expiring patent, and rejected Natco’s double patenting invalidity defense.

The Federal Circuit majority (Chen and Prost, opinion by Chen) reversed and remanded (Rader dissented). The majority’s reversal is predicated on an assumption that the ‘483 patent is an obvious variation of the ‘375 patent, but the details of that conclusion are not discussed. However, the substantive issue of whether the two patents were obvious variants was not the issue here. Rather, this case on appeal turned on the narrow legal question: “Can a patent that issues after but expires before another patent qualify as a double patenting reference for that other patent?” The answer: Yes.

Gilead’s defense of its patents was that the ‘375 patent does not extend the term of exclusivity for the ‘483 patent because the ‘375 patent issued later. The majority dismisses this argument, stating that in the post-June 8, 1995 Uruguay Round (“URAA”) era, patent expiration dates should control the analysis, not patent issue dates. The panel was concerned over “gamesmanship” in patent expiries if Gilead’s argument was accepted, such as filing serial applications on obvious variations. The panel also points to potential irrational outcomes under Gilead’s arguments. For example, if the ‘375 patent hypothetically issued one day before the ‘483 patent, under Gilead’s argument the extra 22 months of patent life of the ‘483 patent would be improper. This could encourage gamesmanship in applicants’ orchestrating patent issue dates, and is contrary to the intent of Congress in the URAA.

The majority states that the ‘483 patent should have been subject to a terminal disclaimer based on the ‘375 patent according to MPEP § 804.I.B.1.

The panel concludes that looking to the earliest patent expiration for patents that are obvious variants “best fits and serves the purpose of the doctrine of double patenting.” Accordingly, an earlier-expiring patent can qualify as an obviousness-type double patent reference for a later-expiring patent under the circumstances of this case. The expiration of the ‘375 patent should trigger “the public’s right to use the invention claimed in it and all obvious modifications of that invention.” Reversed and remanded.

Rader’s dissent asserts that majority decision is an unwarranted expansion of the judicially created doctrine of obviousness-type double patenting. Rader makes general remarks that the court should be more cautious before articulating a “new rule.”

Rader makes two good points. First, if the ‘375 patent never issued, there would be no question of the validity of the full term of the ‘483 patent. Second, Rader points out that the later filing date of the ‘483 patent is subject to ten months of intervening prior art. But Rader doesn’t really tie these points into an argument that the majority was wrong.

Rader also makes policy objections to the majority holding, including that a disclaimer on the ‘375 patent reduces the risk of multiple assignees asserting essentially the same claims against accused infringers, which is not a danger here, and that no one possesses an affirmative right to practice claimed subject matter.

Ultimately, it appears that Rader’s objection is whether the ‘483 patent was an obvious variant of the ‘383 patent. He defers to the examiner, stating that subsequent improvements, if satisfying the criteria for patentability, could “bar the public from practicing some subject matter encompassed by the expiring patents.” But then he concedes that patentably indistinct claims should not bar the public. Rader makes no specific objection to the majority’s reasoning and stops short of saying he would have affirmed the district court.

Comment: I don’t see how the court could have come to a different conclusion here. In the URAA (post June 8, 1995) era, patent expirations must control this kind of analysis. The district court’s reasoning (and Gilead’s defense of its patents) was essentially based on the old 17-year expiration mindset, that patent expiration followed patent issue dates in lock step. That of course is no longer how the system works.

On the specific facts here, it would be more satisfying if the issue of obviousness was discussed, but presumably that will be taken up on remand.