Cellect and Allergan: Obviousness-Type Double Patenting (ODP) in Reexamination and Reissue

Takeaways:

1. ODP in reexamination and reissue remains unpredictable despite Allergan
2. Patent Owners should carefully review ODP rejections to ensure they are proper

Obviousness-type double patenting (ODP) is a legal doctrine intended to prevent the unjustified extension of a patent term through prosecution gamesmanship. Yet, it has become a strong weapon in reexamination practice. In our 2023 PTAB Year in Review article, we noted that In re Cellect, 84 F.4^th 1216 (Fed. Cir. 2023) had the potential to expand the boundaries of substantial new questions of patentability (SNQs) for reexaminations based upon ODP. Cellect involved ODP rejections arising during reexaminations of four family patents, each having patent term adjustment (PTA). The ODP rejections were based upon a later filed (and expired) family patent that did not have PTA. The Court upheld the ODP rejections, explaining that ODP for a patent that has received PTA, regardless of the existence or absence of a terminal disclaimer, must be based on the expiration date of the patent after PTA has been added. See id. at 1229.

Cellect created pause for patentees holding large patent families, such as in the pharmaceutical industry, where patent family holdings commonly have a variety of both PTA and patent term extension (PTE) simultaneously operating. Because ODP can serve as a basis for an SNQ in reexamination, Cellect incentives requesters to file reexaminations on expired or near-expired patents within larger patent families. Moreover, because ODP can be raised during reissue applications, it is expected that the CRU will rely upon Cellect when considering ODP in reissue applications.

The Federal Circuit recently clarified an exception to ODP rejections with its precedential holding in Allergan USA Inc. et al. v. MSN Laboratories Private Ltd. et al., No. 24-1061 (Fed. Cir. Aug. 13, 2024). Patent Owners facing ODP rejections in both reexaminations and reissues should take note of this precedent that makes clear 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” under ODP. Allergan, slip op. at 17.

In Allergan, the ODP issue arose in Delaware District Court under Sun Pharmaceutical’s invalidity contention defense to Allergan’s infringement claim. Sun asserted the ODP invalidity defense against Allergan’s first-filed, first-issued, later-expiring patent in view of two of Allergan’s later filed, later issued, earlier expiring patents claiming the same earliest priority date. The Delaware Court agreed with Sun, noting that it was bound by Cellect and held the patent invalid based upon ODP.

Upon appeal, the Federal Circuit rejected the Delaware Court’s holding and distinguished from Cellect by noting that Allergan presented a different question—under what circumstances can a claim properly serve as an ODP reference. Allergan, slip op. at 15. In reversing, the Court stated, “[t]o hold otherwise – that a first-filed, first-issued patent having duly received PTA can be invalidated by a later-filed, later-issued child patent with less, if any, PTA – would not only run afoul of the fundamental purposes of ODP, but effectively abrogate the benefit Congress intended to bestow on patentees when codifying PTA.” Allergan, slip op. at 20.

While Allergan provides some post-Cellect clarity to ODP, the doctrine remains nuanced, and the line between the cases is thin. Cellect created unpredictability, and Allergan only provides a limited carve-out for a relatively rare fact pattern. Requesters and Examiners may continue to push ODP boundaries or simply get it wrong. For patents under reexamination or reissue which are members of larger patent families, ODP is likely to arise, given these precedential holdings. Patent Owners should carefully review the ODP positions to ensure that the rejections are proper prior to filing any Terminal Disclaimers to overcome ODP.

The authors are also considering how the Office’s request for comments on the use of terminal disclaimers would affect how ODP will be implemented at the Office in view of these Federal Circuit decisions. As the patent bar knows, the Office is considering “[a] proposed rule [where] to overcome double patenting the patentee would need to agree that the patent with the terminal disclaimer will be enforceable only if the patent is not tied and has never been tied through one or more terminal disclaimers to a patent in which any claim has been finally held unpatentable or invalid over prior art. … The proposed rule is prospective in nature and would apply to terminal disclaimers filed on or after the effective date of any final rule.”

The authors note that Cellect has filed a petition for certiorari, and the U.S. Patent and Trademark Office (USPTO) has filed an amicus brief against cert. We will continue to follow this important issue for the patent bar.