Ex parte Baurin — USPTO Appeals Review Panel Reinstates Obviousness-Type Double-Patenting Rejections

Background

Sanofi’s application claims antibody-like binding proteins with specified characteristics. The application was filed in 2020 but traces its patent-term filing date to a 2012 nonprovisional application, so any resulting patent would ordinarily expire in March 2032. The examiner rejected claims 1–18 for obviousness-type double patenting (OTDP) over six related patents or applications in combination with the Klein publication.

The panel focused on U.S. Patent No. 10,882,922. That patent has an April 2017 filing date, issued in 2021, and ordinarily expires in April 2037, plus 70 days of patent-term adjustment. Sanofi presently owns both the application and the ’922 patent, and they share four inventors. It was undisputed that the pending claims would have been obvious over the ’922 patent’s claims in further view of Klein, although the reverse obviousness comparison did not hold.

In November 2024, the original Board panel reversed the examiner. It reasoned that the pending application would expire years before the later-filed ’922 patent and therefore could not extend the ’922 patent’s exclusivity. The Board maintained that result on rehearing in December 2025, over a dissent. The USPTO Director then convened the Appeals Review Panel and authorized briefing from Sanofi and eleven amici on the effect of Allergan USA, Inc. v. MSN Laboratories Private Ltd., the relevance of projected expiration dates, and whether the risk of separate ownership and multiple enforcement suits independently supports an OTDP rejection.

The Court’s Holding

The Appeals Review Panel reversed the earlier Board decisions and affirmed all six OTDP rejections of claims 1–18. The panel held that Allergan did not control because its exception applies to a first-filed, first-issued, later-expiring claim challenged by a later-filed, later-issued, earlier-expiring reference claim having a common patent-term filing date. The ’529 application was not the first actual filing in its family, remained pending rather than first-issued, and had a different patent-term filing date from the ’922 patent.

The panel agreed that issuing the pending claims would not improperly extend patent term: they would expire in 2032, while the ’922 patent would expire in 2037. But it concluded that binding Federal Circuit precedent recognizes a second OTDP rationale—preventing harassment through separate ownership and multiple suits involving patentably indistinct claims. Decisions including In re Fallaux, In re Hubbell, and In re Cellect, the panel said, required the Office to treat that anti-harassment rationale as independently sufficient even when no term-extension problem is apparent. The earlier Board panel therefore erred by dismissing that rationale as immaterial.

The decision is notably candid about the result. The panel stated that, if it were not bound by Federal Circuit precedent, it generally would not use hypothetical ownership splitting and harassment as a freestanding basis for OTDP during examination without evidence of actual abusive conduct. It proposed a possible future framework centered on known filing and term facts, but made that proposal contingent on further Federal Circuit clarification. For now, USPTO personnel must continue following pre-Allergan practice under MPEP § 804 unless the application or patent and the reference are in the same family, share the same patent-term filing date, and the challenged claims are first-filed, first-issued, and later-expiring.

Key Takeaways

• Allergan is a narrow exception, not a general rule that any earlier-expiring claim is immune from an OTDP rejection based on a later-expiring reference.
• Under current Federal Circuit law, the risk of divided ownership and multiple enforcement suits can support OTDP even when the challenged patent would not extend exclusivity beyond the reference patent’s term.
• A terminal disclaimer addresses both recognized OTDP concerns by aligning expiration and requiring common ownership for enforceability.
• The panel’s proposed filing-date framework is policy guidance for a possible future change, not the governing rule unless the Federal Circuit clarifies or changes the anti-harassment doctrine.
• During original examination, the full Allergan fact pattern will be rare because an examiner ordinarily cannot know that pending claims will be first-issued and later-expiring.

Why It Matters

Ex parte Baurin preserves a broad OTDP examination practice at the USPTO while openly questioning one of its foundations. Patent applicants cannot defeat an OTDP rejection merely by showing that their pending claims have an earlier patent-term filing date and will expire before the asserted reference. Unless the case fits Allergan precisely, applicants may still need to distinguish the claims or file a terminal disclaimer carrying common-ownership restrictions. At the same time, the decision gives the Federal Circuit a clear invitation to decide whether speculative anti-harassment concerns should remain sufficient when no timewise extension exists—an issue the panel noted is already before the court in In re Ablynx N.V.