April 24, 2014
The doctrine of obviousness-type double patenting evolved many decades ago, at a time when the natural term of a patent was 17 years from the issue date. Under the old law, earlier-issued patents always had a natural term that expired before that of later-issued patents (i.e., leaving aside maintenance fees, “issued second” always meant “expires second”). The Uruguay Round Agreement Act of 1994 (URAA) changed the patent term rules such that the term of a patent is tied to its earliest effective filing date. After the URAA, it is possible for a later-issuing patent to have a term that expires before that of an earlier-issued patent (i.e., “issued second” but “expires first” is now possible). This will occur when the patent that issued second encounters a longer period of prosecution before the U.S. Patent and Trademark Office (USPTO).
In a decision issued on April 22, Gilead Sciences, Inc. v. Natco Pharma Ltd., the Federal Circuit held that a defendant may raise an obviousness-type double patenting defense based on an earlier-expiring patent, even when the earlier-expiring patent was second to issue. Put another way, a patent that issued second but expires first may be applied against a patent that issued first in an obviousness-type double patenting attack. This decision is significant both for patent applicants and for patent litigants in situations where an applicant has filed multiple related patent applications.
Gilead sued Natco for infringement of U.S. Patent No. 5,763,483, which is directed to antiviral compounds and methods of use. Natco alleged that the ’483 patent is invalid for obviousness-type double patenting in view of U.S. Patent No. 5,952,375, which Gilead also owns. The ’375 patent will expire in February of 2015. The ’483 patent issued before the ’375 patent but will not expire until December 2016, nearly 22 months after the ’375 patent expires. Compared to the asserted ’375 patent, then, the ’483 patent issued second but expires first.
The district court reasoned that Natco could not sustain an obviousness-type double patenting rejection over the ’375 patent because the ’375 patent had a later issue date. For this reason, the court granted summary judgment on Natco’s double patenting defense without substantively analyzing the ’483 patent. After Natco conditionally stipulated to infringement, the court certified its summary judgment ruling for appeal.
On appeal, the Federal Circuit reversed. First, the court explained that the purpose of the double patenting doctrine was to limit a patentee to only a single patent for each invention. The court then observed that the patent statute permits a patentee to own a second patent that is directed to an invention that is patentably indistinct from the invention claimed in a first patent, if the patentee files a terminal disclaimer in the second patent. Such terminal disclaimer will obviate any harm to the public that would be caused by permitting the issuance of multiple patents on patentably indistinct inventions. This is because the term of a second patent that is subject to a terminal disclaimer will not extend beyond the natural expiration date of the first patent.
For the Gilead patents at issue, the court reasoned that once the ’375 patent expires, the public should have the right to use the invention claimed in the ’375 patent and obvious variants of the invention. Because the ’483 patent will not expire until almost two years after the expiration of the ’375 patent, the public’s right to use obvious variants of the invention after the expiration of ’375 patent is impeded in the absence of a terminal disclaimer (under the assumption that the ’483 patent does indeed claim an obvious variant of the ’375 invention). Critically, the court concluded that “it is the comparison of Gilead’s patent expiration dates that should control, not merely the issuance dates.” The court therefore vacated the district court’s grant of summary judgment and remanded for substantive consideration of the obviousness-type double patenting rejection.
The court additionally presented a number of policy-related judgments in support of its analysis. One judge dissented, and argued that these policy-related arguments were spurious. The dissenting judge also argued that the decision would cause unforeseen adverse consequences.
Under Gilead, it is now possible for a patent that issues second but expires first to be applied as a double patenting reference. This case is of interest for litigants confronted with multiple patents on related inventions. Also, although the Gilead case involved two issued patents, there is no language limiting the case to issued patents, and it appears that the case is applicable in the USPTO to pending applications. This appears to create certain issues for patent applicants prosecuting multiple applications on related inventions.
For more information, please contact Fitch Even partner Michael J. Krautner, the author of this alert.
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