USPTO Proposes New Constraints on Inter Partes Review Petitions

The U.S. Patent and Trademark Office (“USPTO”) recently proposed rules[1] governing inter partes review (“IPR”).[2] If adopted, these requirements would:

• sharply limit institution of IPRs based on actual or perceived parallel litigation—even if unrelated to validity challenges raised in a petition—and
• expand the estoppel effects of IPRs, beyond what Congress has legislated.

For background, IPRs are an administrative proceeding enacted by Congress in 2012 to lower the barriers and risks to asserting invalidity defenses to existing patents. A challenger can file a petition to “institute” (in other words, undertake) review of existing patent claims based on specific prior art references. If instituted by the Patent Trial and Appeal Board (“PTAB”), IPRs typically result in a final written decision, either invalidating or upholding the challenged claims.

Proposed Amendments to IPR Rules

The proposed amendment would add four sections to the current regulation. Beginning with the first proposal, the first addition (section (d)) would require IPR petitioners to stipulate that if the IPR is instituted, the parties and their privities will not raise any invalidity challenges under 35 U.S.C. §§ 102 or 103 in other patentability proceedings.[3] This is notable because it applies estoppel upon institution of the IPR, even if a final written decision is not issued, and goes further than statutory estoppel,[4] which only applies to final written decisions. Thus, a petitioner whose IPR is instituted but does not reach final written decision would be estopped under the regulation—but not by statute—from asserting any Section 102 or 103 arguments in subsequent civil suits. It also goes beyond the statutory “Requirements of Petition,” 35 U.S.C. § 312(a), by adding the stipulation as a new requirement.

The second and third additions (proposed sections (e) and (f)) limit the situations where IPRs can proceed. Both prohibit institution of IPRs based on parallel proceedings. Section (e) prohibits petitions where a challenged claim has already been found not invalid by a U.S. District Court or other tribunal; section (f) prohibits institution where it is “more likely than not” that a U.S. District Court or the PTAB will soon reach a decision on the merits of any claim challenged in the petition. While the theory here is reasonable, it does not account for the grounds of the invalidity challenge in the parallel proceeding. For example, if a patent claim prevails over a challenge under Section 102 or 103 by Reference A in a U.S. District suit, this rule would prohibit later IPR challenges based on Refence B, C, D, etc., even if those are completely different than Reference A. This goes far beyond the understanding of collateral estoppel—issue preclusion—and falsely equates validity as to one reference with validity against any reference and without limitation to the same challenging party.

Finally, the fourth addition (proposed section (g)) permits the USPTO Director’s discretionary exceptions to the other proposed sections. For example, substantial changes in statute or in precedent from the Supreme Court of the United States would provide sufficient basis to institute IPR at the Director’s discretion, notwithstanding a prior merits decision on validity. Exceptions would not apply based on new prior art, new expert testimony, new Federal Circuit law or new legal arguments. This raises the question whether a substantial change in Supreme Court precedent would occur based on a Federal Circuit decision where the Supreme Court subsequently denied certiorari—effectively affirming the Federal Circuit but without issuing a merits decision.

Notable Comments

American Bar Association (ABA) IP Section - The ABA generally supports improving efficiency in PTAB proceedings but opposed the proposed rules as drafted. Their main concern is that the changes impose overly broad restrictions, such as requiring petitioners to waive certain invalidity arguments in other forums, which they believe exceed the USPTO’s statutory authority and risk undermining the balance Congress intended under the AIA.

Association for American Innovation (AAI) - AAI strongly supports the proposed amendments, emphasizing that they are necessary to curb serial and parallel PTAB petitions. AAI argues these changes will protect small innovators from abusive tactics by large corporations, reduce litigation costs and restore the AIA’s original goal of providing a fair and efficient alternative to district court litigation.

Roku Inc. - Roku opposed the proposed rules, arguing they would unjustly restrict access to AIA proceedings and effectively insulate weak patents from review. Roku’s primary concern is that the rules would create sweeping bars on IPR institution and force stipulations that limit valid defenses in other forums, which they believe contradicts the AIA’s purpose of providing an efficient mechanism to correct erroneously issued patents.

Impact on Patent Litigation

If adopted, these amendments would make IPR institutions more difficult and would attach more consequences to institution. Before filing an IPR petition, patent challengers would want to ensure that they have marshaled the strongest prior art under Sections 102 and 103, because a “second bite at the apple” is extremely unlikely, either through a second IPR or in a subsequent U.S. District Court suit.

Additionally, because the proposed amendments apply estoppel upon institution of the IPR—not upon the final written decision—patent challengers should be more wary about pursuing IPRs at all. This is doubly true in light of USPTO Director John Squires’ recent assertion of power to retroactively vacate a final written IPR decision.[5] If IPR institutions can be retroactively vacated (before or after a written decision issues) and this proposal is effective, IPR petitioners would be estopped from asserting defenses in U.S. District Court even though they didn’t get the benefit of a final written IPR decision. This sharply limits the benefit of IPRs, potentially leaving a patent challenger better off simply in District Court.

By undermining the value of IPRs, these amendments will force more disputes into District Court, which is less favorable to patent challengers than IPRs due to differing burdens of proof and claim interpretation standards, as well as higher costs. These amendments would also make alternative administrative proceedings more appealing. If the amendments are adopted, we would expect an uptick in applications for ex parte reexaminations and post-grant reviews.

The comment period on the proposed amendment closed on December 2, 2025. A final rule is expected to follow. If you have questions about these developments, contact the authors of this article or your Dinsmore intellectual property attorney.