On October 16, 2025, the U.S. Patent and Trademark Office (USPTO) issued a Notice of Proposed Rulemaking (NPRM) in relation to inter partes review (IPR) proceedings before the Patent Trial and Appeal Board. Focusing on “promot[ing] fairness, efficiency, and predictability in patent disputes,” some of the key proposed changes include:

• Petitioner Stipulation Requirement: IPR Petitioners must file a stipulation agreeing not to raise §§ 102 or 103 invalidity arguments elsewhere, such as district court, if the IPR is instituted,
• Bar on IPR Institution After a Prior Validity Finding: Essentially refocusing IPRs on claims that have not already been reviewed in another proceeding in order to reduce duplicative review, and
• Parallel Proceeding Rule: IPRs will not be instituted where another forum is likely to resolve the same invalidity issues first.

The Proposal emphasizes that serial or parallel proceedings are problematic, “wasteful,” and, as a result, “consume Office and party resources re-litigating issues that the Office is considering, has already considered, or that are being litigated elsewhere[.]” Moreover, it stresses protecting the integrity of patent rights by highlighting that IPRs jeopardize even strong patents when subject to multiple challenges and repeated review.

One of the noted concerns relating to repeated de novo patentability review is that “reasonable minds may, and frequently do, disagree[.]” Essentially, patents can become unreliable when subject to repeated review due to statistical attrition, as repeated challenges slowly chip away at patent reliability, thereby making it challenging for patents to serve their economic function.

But if reasonable minds frequently disagree on validity, does this not reflect an inconsistent USPTO examination in the first place? Additionally, whether another parallel proceeding is “likely” to resolve validity issues first also presents subjectivity and unpredictability concerns—the exact type of concerns the NPRM seeks to mitigate yet seemingly introduces. More importantly, while preventing duplicative IPRs may improve efficiency, the risk of new challengers being unfairly blocked is high. Should parties be bound by the initial effort of a prior petitioner in the event the prior petitioner has done a poor job, for example, by failing to identify the most relevant prior art? This rule may, in fact, introduce a new problem: making reliable adjudication of invalidity dependent on who filed first rather than the merits.

The NPRM is somewhat of a new spin on the now officially withdrawn 2024 Notice of Proposed Rulemaking issued by Kathi Vidal, and comes almost seven months after the March 26, 2025 Interim Processes for PTAB Workload Management Memorandum, which introduced procedural changes relating to discretionary denials for IPRs and PGRs. Specifically, the bifurcated institution decision process outlined in the March memorandum gives the USPTO Director discretionary denial power—in consultation with at least three PTAB judges—as opposed to one panel evaluating both discretionary and merits issues together. Yet it seems the March 2025 interim guidelines regarding discretionary denials have already made Board proceedings less predictable and potentially less favorable for petitioners. The Proposed Rule may further compound those difficulties.

That said, not all aspects are negative, as the new NPRM still includes extraordinary circumstance exceptions permitting the institution of IPRs despite the proposed bars in events such as where a prior challenge was made in bad faith. With the comment period now officially open as of October 17, 2025, Thomas Horstemeyer will be watching for further developments.

See the full Proposed Rule here: https://www.federalregister.gov/public-inspection/2025-19580/rules-of-practice-before-the-patent-trial-and-appeal-board.