Key Takeaway: The PTO Director’s sua sponte rehearing of Ex parte Baurin raises questions regarding the scope of Allergan v. MSN, Examiners’ role in obviousness-type double patenting rejections, and the underlying policy justifications for these types of rejections.
The Director of the U.S. Patent Office, John Squires, entered an order on Thursday, March 6, 2026, stating that he will convene a sua sponte rehearing regarding the Board’s 2025 decision regarding obviousness-type double patenting (ODP) and its interaction with Patent Term Adjustment (PTA) law in Ex parte Baurin.
Patent term adjustment arises under 35 U.S.C. § 154(b) and can increase patent term to compensate for undue USPTO delays during the prosecution of a patent application. PTA effectively extends the expiration date by the amount of undue USPTO delay in the absence of any applicant-caused delays (for example, taking an extension to respond to an Office Action). The interplay of ODP and PTA has been at issue, in recent years, or example in the In re Cellect 81 F.4th 1216 (Fed. Cir. 2023) and Allergan v MSN Laboratories, 111 F.4th 1358 (Fed. Cir. 2024) decisions.
In 2024, the Board in Ex parte Baurin reversed the Examiner’s ODP rejection of claims in U.S. Patent Application No. 17/135,529 based on U.S. Patent No. 10,882,922. The Board held then that the ‘922 Patent was not a valid ODP reference against the ‘529 Application because the ’922 Patent was based on an application filed after the ’529 Application despite that the ’922 Patent had a later expiring date than would a patent issuing from the ’529 Application. The Board relied on Allergan. In Allergan, the Court of Appeals for the Federal Circuit had held that a later-filed, later-issuing patent is not a valid ODP reference against an earlier-filed, earlier-issuing patent where both patents belong to a common priority chain and the purported ODP reference was the first patent to claim a new compound. The Board acknowledged that “[w]hile the facts of Allergan are somewhat different than here because the ‘922 Patent and the [‘529] application before us do not share a priority date or even stem from the same application family, we find the reasoning compelling.”
The Examiner requested reconsideration of the Board’s decision, arguing, in part, that (1) the decision “misapprehends the holding of Allergan,” and (2) the decision is “not consistent with” MPEP § 804 and § 804.02, and (3) the conclusion “that the risk of separate ownership is ‘immaterial’ is not supported by case law or USPTO guidance.”
In 2025, the PTAB denied the Examiner’s request for reconsideration, stating (1) the decision relied on the reasoning in Allergan rather than the fact-specific holding, (2) that the MPEP is a guidance document which “does not have the force and legal effect of law or the force of the rules in Title 37 of the code of Federal Regulation” and that Examiners may calculate, and rely upon, the expected expiration date of an application by including both the likely PTA and any Patent Term Extension (PTE) (though this extension of term is not affected by a terminal disclaimer) to see if a patent is a qualifying ODP reference to limit patent term, and (3) that the risk of separate ownership is not a reason by itself to justify a non-statutory double patenting rejection ab initio, citing to In re Van Ornum 686 F.2d 937, 214 USPQ 761 and In re Fallaux 64 F.3d 1313 (Fed. Cir. 2009).
Pursuant to Director John Squire’s order, the sua sponte rehearing will cover (1) the applicability, if any, of Allergan USA, Inc. v. MSN Laboratories Private Ltd., 111 F.4th 1358 (Fed. Cir. 2024), to the facts of this appeal, and consideration of what constitutes “first-filed” for purposes of ODP under facts different than those presented in Allergan; (2) whether an Examiner should determine projected expiration dates to support OTDP rejections during prosecution; and (3) whether the risk of separate ownership and preventing potential harassment by separate owners of claims to obvious variants of an invention is an independent basis that supports an ODP rejection.
This rehearing will address serious questions in the wake of In re Cellect and Allergan v. MSN. The court’s analyses in these cases appear to be fact specific, and any insight into how PTA will be treated for cases with different facts should help clarify the applicability of ODP where PTA is involved. While ODP is a judge-made doctrine, based largely on the policy consideration that an invention and its obvious variants may be protected by only one patent, clarification is needed to understand how ODP may be influenced by statutory PTA.
Following the decision, practitioners should be better prepared to adapt prosecution strategies on clarified rules or policy considerations concerning PTA and ODP, especially when handling patents with differing priority dates or unrelated application families. The PTO has received numerous amicus curiae briefs in response to the Director’s order.
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