By: Nayyer Siddiqi
The Federal Circuit recently issued a decision in Allergan USA, Inc. et al., v. MSN Laboratories Private Ltd., et al., No. 24-1061 (Fed. Cir. Aug. 13, 2024), pertaining to the issue of obviousness-type double patenting and patent-term adjustment. The Court’s decision in Allergan is a positive outcome for patentees, who were concerned that patent-term adjustments given to “first-filed, first-issued” patents would be taken away by later-issued child patents that expired earlier but shared the same priority date. While the Court’s decision addressed other issues, this update focuses solely on reviewing the Court’s opinion on the intricate relationship between obviousness-type double patenting and patent-term adjustment for patent applications and their continuations.
The Federal Circuit’s ruling here provides important guidance on how patentees approach matters in which a series of patent applications are being contemplated.
What is Patent-Term Adjustment?
Delays during the examination of a patent application in the U. S. Patent and Trademark Office may be detrimental to applicants. Patent-term adjustment allows the term of a U.S. patent to be extended, with the intent being to compensate for delays in the U. S. Patent and Trademark Office during the prosecution period.
What is Obviousness-Type Double Patenting?
Obviousness-type double patenting is a judicially created doctrine that prevents inventors from obtaining multiple patents for claims that are not patentably distinct from the claims in a prior or “parent” patent. The policy aims to ensure that a patentee does not obtain multiple patents on a single invention in order to improperly extend the patent term. The U. S. Patent and Trademark Office generally requires that applicants file a terminal disclaimer in order to overcome a rejection for obviousness-type double patenting. The terminal disclaimer functions as a mechanism to cut short the time period (or patent term) extending beyond the expiry of the statutory term of the parent patent.
The Allergan Case
The patent at issue in Allergan was US Patent No. 7,741,356 (referred to hereinafter as patent ‘356), which is directed towards opioid receptor modulators and covers eluxadoline, the active ingredient in its Viberzi™ tablets. Various continuation applications were filed claiming the benefit of the same priority date as the ’356 patent, including continuation applications resulting in the following two “child” patents: US Patent No. 8,344,011 and US Patent No. 8,609,709. The ‘356 patent (“parent”) was awarded considerable patent-term adjustment time. However, neither of the child patents received patent-term adjustment and were set to expire before the parent patent. Allergan’s opponents successfully argued at the district court level, based on In re Cellect LLC, 81 F. 4th 1216 (Fed. Cir. 2023) which is discussed below, that the two child patents were obviousness-type double patenting references that rendered a certain claim (claim 40) of the parent patent invalid.
On appeal, the Federal Circuit reversed, finding that the claims of the two child patents were not proper obviousness-type double patenting references that could be used to invalidate claims of the parent patent. The Court held that a “first-filed, first-issued, later-expiring claim cannot be invalidated by a later-filed, later-issued, earlier-expiring reference claim having a common priority date.” According to the Court, this was the only conclusion consistent with the purpose of the obviousness-type double patenting doctrine, which is “to prevent patentees from obtaining a second patent on a patentably indistinct invention to effectively extend the life of a first patent to that subject matter.”
At first glance, the Allergan decision appears to be at odds with the Federal Circuit’s prior ruling in In re Cellect LLC, 81 F. 4th 1216 (Fed. Cir. 2023), which held that a patent benefitting from patent-term adjustment (under 35 US Code § 154(b)) may be invalidated for obviousness-type double patenting over patents in the same family that expired earlier. In its decision in Allergan, the Federal Circuit distinguished the questions presented in In re Cellect from Allergan, finding that “Cellect does not address, let alone resolve, any variation of the question presented here—namely, under what circumstances can a claim properly serve as an ODP reference—and therefore has little to say on the precise issue before us.” The analysis in In re Cellect had not considered when the patents were granted (or filed), and therefore did not evaluate whether the patentee had intended to unreasonably extend the patent term.
Takeaway
The Allergan ruling establishes that “a first-filed, first-issued, later-expiring claim cannot be invalidated by a later-filed, later-issued, earlier-expiring reference claim having a common priority date.” Furthermore, the Allergan ruling provides that the first-filed, first-issued patent in a family “sets the maximum period of exclusivity for the claimed subject matter and any patentably indistinct variants.”
One takeaway here is that, in a matter where a series of patent applications are being contemplated, it would make sense for patentees to pursue the most important claims in the patent application that is filed first. Given that In re Cellect is still pending before the Supreme Court, there may be more updates and nuances added to the interplay between obviousness-type double patenting and patent-term adjustment for patent families in the future.