Proposed Revision To PTAB Rules And How The Revisions Could Limit IPR Challenges

On October 17, 2025, the US Patent and Trademark Office (USPTO) proposed changes to specific sections in 37 C.F.R. § 42.108, which provide the rules of practice for inter partes review (IPR) before the Patent Trial and Appeal Board (PTAB). The proposed rules aim to limit IPR proceedings to patent claims that have not previously been challenged in litigation and those that were the subject of prior litigation that was resolved early. The goals of the proposed rule changes include (1) re-establishing IPR proceedings as a true alternative to district court litigation, thereby limiting parallel and serial validity challenges, reducing litigation costs, conserving USPTO resources, and ensuring IPR proceedings act as Congress intended, and (2) ensuring reliability of patent rights and incentives to invest in patented technology. The notice provides a 30-day comment period; the deadline for commenting is November 17.

KEY TAKEAWAYS

• Required Stipulation for IPR: Petitioners must file a stipulation with the PTAB and all other tribunals where it is or will litigate regarding the challenged patent stating that if review is granted, the petitioner (including any real parties in interest and those in privy of the petitioner) will not challenge the invalidity or patentability of the challenged patent under 35 U.S.C. §§ 102 or 103 in any other proceedings.
• IPRs Not Instituted or Maintained If:
• • Challenged Claims Found Valid in Prior Proceedings: IPR will not be instituted or maintained if a challenged claim was found not invalid under §§ 102 or 103 in a US district court or the US International Trade Commission (ITC), was found not unpatentable by the PTAB, or was found patentable in an ex parte reexamination. Additionally, if the challenged claim was originally found unpatentable or invalid but that decision was later reversed by the Federal Circuit, then an IPR will not be instituted or maintained. Even if the petitioner had no involvement in the prior proceedings, an IPR will not be instituted if the challenged claim was found valid in a prior proceeding.
  • Parallel Litigation: IPR will not be instituted or maintained if it is "more likely than not" that, prior to the due date for the final written decision, a party challenges the patent under §§ 102 or 103 in a district court trial, the ITC makes a determination with respect to the challenged claim, or the PTAB issues a final written decision.
• Extraordinary Circumstances: The USPTO Director may institute IPR if extraordinary circumstances warrant it; such circumstances include when the prior challenge preventing institution was brought in bad faith or is considered irrelevant because of a substantial change in a statute or US Supreme Court precedent. Notably, new prior art, expert testimony, caselaw (other than that noted above), or legal arguments do not constitute extraordinary circumstances under the proposed rule changes. A prior challenger's failure to appeal is also not an extraordinary circumstance.
• Potentially Fewer IPR Proceedings in the Future: The proposed rule changes will likely decrease the number of IPR petitions because petitioners will opt to raise arguments under §§ 102 or 103 in other proceedings outside of PTAB.

STRATEGIC CONSIDERATIONS FOR PRACTITIONERS

FOR PATENT OWNERS:

• Submit Comments in Support of Proposed Changes: Because these proposed rule changes will likely reduce the number of IPR petitions both instituted and maintained, patent owners should submit comments expressing their support of the proposed modifications. By limiting the number of IPR petitions and thus challenges to patent rights, the proposed changes will help limit the serial challenges to patents, which increase incentives to invest in patented technology.
• Defense to IPR Petitions: If these proposed changes are approved, patent owners can use these rules to defend against new or ongoing IPR petitions. Patent owners should fully investigate a patents litigation history to determine if the existence of previous validity challenges can be used as a defense to IPR petitions.
• Advantages for Investors: If certain IPR challenges can no longer be brought against a patent because of prior adjudications, licensing or otherwise monetizing the patented technology becomes more certain.
• Challenges in Bad Faith to Estop Future Institution of IPR Proceedings Would Be Ineffective: Because the exception for "extraordinary circumstances" is narrow, encouraging bad faith validity challenges in other venues would not result in the Director or PTAB refusing to institute review.

FOR PETITIONERS:

• Submit Comments Against the Proposed Changes: Because these proposed modifications will likely decrease institution of IPRs, patent challengers should submit comments expressing their disagreement with the proposed modifications. If the proposed rule changes are approved, the options for §§ 102 and 103 challenges are significantly narrowed.
• Choose Venue for Patent Challenges Wisely: If the petitioner wishes to institute an IPR to challenge a patent's validity or patentability under §§ 102 or 103, the petitioner should weigh the pros and cons of having to stipulate that they will not make any invalidity arguments concerning the challenged claim in other venues.
• Full Investigation of Patent's Litigation History: Petitioners must investigate whether challenges were previously brought against a subject patent prior to raising further IPR challenges.

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This Mayer Brown article provides information and comments on legal issues and developments of interest. The foregoing is not a comprehensive treatment of the subject matter covered and is not intended to provide legal advice. Readers should seek specific legal advice before taking any action with respect to the matters discussed herein.