USPTO Appeals Panel urged by Sanofi to Uphold Ex Parte Baurin’s Approach to ODP Analysis

USPTO Appeals Panel urged by Sanofi to Uphold Ex Parte Baurin’s Approach to ODP Analysis

The CAFC explained that the purpose of the ODP doctrine 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”—not to block a first-issued patent that expires later, as was the case here

Amicus briefs in the U.S. Patent and Trademark Office’s (USPTO’s) review of issues raised by a 2025 Patent Trial and Appeal Board (PTAB) rehearing decision regarding the judicially-created doctrine of obviousness-type double patenting (ODP) were due on Friday, March 27. At least one amicus is urging the Office to affirm the decision’s holding and clarify that the focus should be on “whether there is any unjustified extension of term when determining if an ODP rejection is appropriate” in order to create more consistent outcomes in examination and to harmonize the approaches of the PTAB and examining corps. The USPTO announced earlier this month that it will convene an Appeals Review Panel (ARP) to examine the issues raised by Ex Parte Baurin issued on December 18, 2025. There, the PTAB denied an examiner’s request for reconsideration of the Board’s November 8, 2024 decision, reversing the examiner’s ODP rejections of several claims of a certain US application directed to antibody-like binding proteins. The reference patent the examiner relied upon for its ODP analysis was not a proper ODP reference because it was later filed and later expiring than the application in the present case.

The rejection was based on the Board’s interpretation of Allergan USA, Inc. v. MSN Labs. (Fed. Cir. 2024), which 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.” The CAFC explained that the purpose of the ODP doctrine 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”—not to block a first-issued patent that expires later, as was the case here. The appellant Sanofi in its response to the Squires’ order also addressed the examiner’s argument about future separate ownership or withdrawal of terminal disclaimers which the Board found to be an insufficient basis to support an ODP rejection and irrelevant where the ODP reference is not proper. The PTAB reportedly wrote in its rehearsing decision, “While there may be a policy concern of risk of separate ownership underlying the non-alienation provision for terminal disclaimers, no court has held that risk of common ownership is a sole justification for upholding an ODP rejection that is not based on a proper reference patent.”