PTAB ARP Issues Precedential Decision on Obviousness-Type Double Patenting, Asks CAFC for More Clarity

An Appeals Review Panel (ARP) of the U.S. Patent and Trademark Office’s (USPTO’s ) Patent Trial and Appeal Board (PTAB) today issued a decision on sua sponte rehearing reversing a PTAB decision that had itself reversed an examiner’s rejection of claims for obviousness-type double patenting (OTDP). The decision has been designated as precedential and was authored by USPTO Director John A. Squires, PTAB Chief Judge Kalyan Deshpande, and PTAB Acting Deputy Chief Judge Michelle Ankenbrand.

The USPTO announced in March that it would convene the 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 OTDP rejections of several claims of U.S. Application No. 17/135,529, directed to antibody-like binding proteins. The Board found that the reference patent the examiner relied upon for its OTDP analysis, U.S. Patent No. 10,882,922, 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.

Amici weighed in in late March. One amicus brief, authored by Anthony Prosser of Knowles Intellectual Property Strategies, speaking on his own behalf and not for his company, told the ARP  that “[o]ver a dozen judges have dealt with non-statutory obviousness type double patenting (ODP) since the Allergan v. MSN decision and have reached a similar conclusion as the Board in Ex parte Baurin.”

But today’s decision, while acknowledging that the appellant and amici arguments were “not without merit,” concluded that “the OTDP exception Allergan establishes does not apply to the facts here.”

Here, said the ARP, “the ‘first-filed’ prong is not satisfied because the ’529 Application does not have the first actual filing in its family, as was the case for the challenged patent in Allergan.” The claims of the ‘529 patent are also not “first-issued” because the application is still pending. And the ‘529 and ‘922 patents have different patent term filings dates and thus do not satisfy the “common-priority date” prong.

With respect to whether the ‘922 patent could serve as an OTDP reference against the claims, the ARP said the Board’s holding that the OTDP doctrine is inapplicable where issuance of the claims on appeal would not raise term-extension concerns failed to consider other rationales underpinning the OTDP doctrine. The decision explained:

“[T]he anti-harassment rationale is a second justification for the doctrine…. The Examiner cited the risk of separate ownership and the anti-harassment rationale as support for the OTDP rejections on appeal, but the Board dismissed that rationale as immaterial… We conclude that the Board erred in dismissing the anti-harassment rationale as inadequate to support the Examiner’s OTDP rejections.”

The anti-harassment rationale specifies that “preventing harassment from separate lawsuits brought by multiple assignees asserting patents covering the same invention or obvious variants thereof” is another policy consideration behind the OTDP doctrine.

According to the panel, U.S. Court of Appeals for the Federal Circuit (CAFC) precedent supports its position, but the decision also later noted that “[i]f, contrary to our conclusion here, the Federal Circuit’s precedents should not be read as permitting OTDP rejections based on the anti-harassment rationale where no term-extension concern is apparent, the Office would welcome that clarification from the court.”

To that end, the decision went on to comment on the future framework for consideration of  OTDP at the Office, and “to propose a possible framework for an approach to OTDP that is reasonably administrable by examiners and more predictable to our stakeholders, should the Federal Circuit clarify that OTDP rejections cannot be based solely on the anti-harassment rationale.”

Because the Uruguay Round Agreements Act (URAA) reduced concerns about OTDP, “the ARP is of the view that the Office’s review for OTDP should be more streamlined, predictable, and, to the extent possible, aimed at mitigating the term extension issues the court has flagged for post- URAA patents,” said the decision.

The URAA, effective June 8, 1995, changed patent term from 17 years from a patent’s issuance to 20 years from the patent’s earliest claimed priority date. “By tying the putative expiration date of related patents to a single common filing date, that change in the law curbed abuses in continuation practices where, previously, related applications claiming essentially the same subject matter might be filed seriatim with each newly-issued patent getting a new 17-year term—effectively extending the patent monopoly well beyond the original life of the first-issued patent,” explained the decision. However, the ARP acknowledged that the CAFC has still recognized the OTDP doctrine as important even for post-URAA patents.

The ARP’s decision further noted that, were it not bound by CAFC precedent, it would “clarify that the risk of separate ownership and hypothetical harassment generally should not form a standalone basis for OTDP rejections during examination.” The decision continued:

“This is so because, absent evidence that an applicant/patentee has engaged in splitting ownership to patents covering obvious variants of the same invention and that the public has been subject to separate lawsuits on such patent, the Office is just speculating.”

With respect to patents from different families, the Office suggested taking an approach in which the examiner would ask the following question:

“Does a putative OTDP reference have a later patent term filing date than the patent term filing date of the application under examination? If the answer is ‘yes,’ the Office’s OTDP analysis under a term-extension rationale for that alleged reference ends.10 If, alternatively, the reference has an earlier patent term filing date, the analysis may proceed to a comparison of the claims and, as appropriate, a rejection for OTDP may be made.”

For patents within the same family, the approach would focus on:

“actual filing dates (and issue dates, if known, as applicable). Applications with later actual filing dates can be rejected for OTDP over their earlier-filed parent applications or patents within the family, but such rejections would not work in reverse. This approach would better ensure that later-filed patents will not have a term that extends longer than their parent patents claiming substantially the same innovation.”

Finally, the decision recommended “circumscribing” the anti-harassment rationale if it is not abandoned completely. This could include requiring “actual evidence of previous ownership splitting and harassment resulting from the conduct of a particular applicant before the anti- harassment rationale could be wielded on its own against that applicant as a basis for OTDP rejections,” for example, or requiring examiners to “establish the obviousness of the challenged claims and reference claims over each other—essentially a two-way test—before a standalone anti-harassment rationale could form the basis for OTDP at the Office.”

However, these changes are contingent upon further clarification and guidance from the CAFC, said the decision.

Ultimately, the ARP reversed the PTAB’s rehearing decision and reinstated the examiner’s rejections of the claims at issue.