Petitioners challenging patents in IPR procedures may use various strategies to improve the likelihood of avoiding discretionary denial. One such strategy is to identify a material error. In this alert, we explore several cases highlighting material errors for petitioners and patent owners to be aware of during IPR proceedings. We then discuss three recent USPTO publications affecting the institution of IPR and PGR proceedings, as well as the requirements for identifying the RPI at the time of petition filing. These cases and notices reflect the USPTO’s shift toward stricter IPR procedures.
In IPR proceedings, identifying a material error often involves referring to cited prior art that the USPTO examiner did not properly consider during prosecution. However, the PTAB has held that “[i]f reasonable minds can disagree regarding the purported treatment of the art or arguments, it cannot be said that the Office erred in a manner material to patentability.” Advanced Bionics, LLC v. MED-EL Elektromedizinische Geräte GmbH, IPR2019-01469, Paper 6 (PTAB February 13, 2020). The four cases summarized below illustrate examples where petitioners avoided discretionary denial by successfully demonstrating a potential material error that amounted to more than a disagreement of reasonable minds.
The petitioner showed material error by noting that the USPTO issued the challenged independent claim 1 with incorrect language. Claim 1 did not recite the same subject matter identified in the Notice of Allowance. The applicant attempted to correct this discrepancy in a Rule 312 post-allowance amendment, but the patent still proceeded to issue with the incorrect claim language. During the 13 years the patent was in force, the patent owner requested a Certificate of Correction to fix typographical errors in the patent but did not correct the error in claim 1. As a result, the deputy director ruled that the settled expectations did not outweigh the material error.
The petitioner contended that the USPTO materially erred during prosecution because the patent examiner overlooked a reference disclosing the purported “unobvious improvement over the art of record” cited in the reasons for allowance. The deputy director agreed and concluded that it is an efficient use of resources to review this potential error in the challenged patent and its divisional patent. The presence of the reference in an Information Disclosure Statement (IDS) did not undermine the finding of a material error. The petitioner suggested the examiner’s error may have been due to distorted versions of relevant diagrams from the reference the patent owner submitted with the IDS.
Ascentcare Dental Products, Inc. v. Sometex, LLC, IPR2025-01104, -1175 (October 17, 2025):
A patent examiner’s misreading of a prior art reference in a rejection during prosecution of a challenged patent can also amount to material error. The patent examiner rejected the independent claim over the reference but concluded that dependent claims included allowable subject matter. The petitioner presented evidence, however, that the reference disclosed the purportedly allowable subject matter, which applicant incorporated into the issued claims. The petitioner’s evidence was an annotated copy of figures from the reference, illustrating how the depicted components mapped to the claim limitation.
Apple Inc. v. Advanced Coding Technologies LLC, IPR2025-01070, -01103, -01158 (October 17, 2025):
In a mixed decision, the deputy director referred one of Apple’s three IPRs to the PTAB based on a persuasive showing that the USPTO materially erred during prosecution. The patent examiner initially rejected all claims over prior art. Applicant responded by amending the independent claims. In the subsequent office action, the examiner again rejected the independent claims over the same art but in apparent oversight did not address a pair of dependent claims. Applicant responded by noting that the pair of dependent claims were not rejected and incorporated their subject matter into the independent claims. The examiner allowed the amended claims without any discussion of the previous prior art rejection of the dependent claims. Since the basis on which the examiner appeared to have allowed the claims was the subject matter of the dependent claims, Director Squires found the examiner’s oversight appeared to be an error material to the patentability of the challenged claims.
These cases highlight material errors for petitioners and patent owners to be aware of during IPR proceedings. For petitioners, identifying one of these potential errors may overcome other factors favoring discretionary denial, even for patents in force for some time. A good material error argument may become more important in view of three recent USPTO publications relating to IPR proceedings.
An October 17 memorandum to the PTAB released by the USPTO states that Director Squires will personally make all institution determinations in IPR and PGR cases, covering both discretionary considerations and the merits. Routine institution decisions will be issued in the form of summary notices without written explanations of the reasoning. In limited situations involving novel or important factual or legal issues, such as complex claim construction questions, priority determinations, or disputes over the real party in interest, the director may issue a detailed decision or refer the matter to one or more PTAB judges. The memorandum supersedes prior guidance to the extent that (1) routine decisions on institution will be limited to summary notices and (2) merit-based decisions on whether to institute petitions will not be referred to a three-member panel of the PTAB. The process for briefing discretionary and statutory considerations will remain the same, and petitions that were referred to the PTAB prior to October 20, 2025, will remain with a three-member panel.
This change centralizes control of institution decisions in the director’s office and reflects an effort to create greater procedural efficiency. However, because summary notices will not include detailed explanations, parties will have less insight into the USPTO’s reasoning. The lack of detailed guidance could make it harder to anticipate how similar issues will be evaluated in future proceedings and in related district court disputes.
Also on October 17, the USPTO published a Notice of Proposed Rulemaking (NPRM) that would impose new limits on when IPRs may be instituted. Under the proposal, every IPR petitioner would be required to file a stipulation at the USPTO and any other tribunal where they are litigating the same patent(s) agreeing to forego all anticipation or obviousness challenges if the PTAB institutes trial. Institution would be denied if the challenged claim (or an independent claim from which the challenged claim depends) had previously survived a validity challenge in district court, the U.S. International Trade Commission (ITC), a PTAB final written decision, or a third-party reexamination, or if a challenged claim’s invalidity finding was reversed by the Federal Circuit. Institution would also be denied when it is more likely than not that either a district court trial will occur, the ITC will issue an initial or final determination, or the PTAB will issue a final written decision in another proceeding before it renders a final written decision on the requested IPR.
The NPRM would allow a panel of the board to refer a matter to the director for potential institution in light of “extraordinary circumstances,” including bad-faith prior challenges intended to block future petitions, or a substantial change in a statute or precedent of the U.S. Supreme Court. New prior art, new expert testimony, new case law, or a challenger’s failure to appeal would not qualify as extraordinary circumstances.
If adopted, these changes would restrict the number of times a patent can be challenged and may eliminate a petitioner’s ability to have the PTAB institute an IPR even where that petitioner did not itself previously challenge the patent. The stipulation required would also create a de facto estoppel for petitioners that is broader than the statutory estoppel provided under the America Invents Act.
An October 28 memorandum focuses on the requirement that petitioners identify all RPIs in their petitions before the director will institute trial. Director Squires removed the precedential designation from SharkNinja Operating LLC v. iRobot Corp., IPR2020-00734, Paper 11 (PTAB October 6, 2020), which allowed petitioners more flexibility to supply RPI information after filing. He designated as precedential most of the 2015 decision in Corning Optical Communications RF, LLC v. PPC Broadband Inc., IPR2014-00440, Paper 68 (PTAB August 18, 2015) (except for § ILE.I), which requires complete RPI disclosure before institution. Director Squires stated that this stricter requirement responds to national security concerns arising from an increase in petitions filed by or connected to foreign adversaries, including possible state-sponsored activity. He explained that opacity in the chain of ownership or control may facilitate technology transfer in violation of U.S. law, and that requiring identification of all RPIs before institution helps eliminate such opacity.
One consequence of this change is that if a petitioner must amend a filing to include additional parties, the official filing date may be considered the date of the amendment. If that new date falls after the statutory deadline for filing an IPR or PGR petition, the proceeding could be dismissed as untimely. As a result, petitioners should take care to identify all relevant RPIs at the time of filing.
The recent USPTO memoranda signal a shift in IPR and PGR practice toward centralized control of institution decisions, stricter disclosure obligations, and expanded grounds for discretionary denial. Additionally, the cases discussed above illustrate how petitioners may improve the chance of institution by identifying and substantiating material errors in patent prosecution. Petitioners should also anticipate how codified discretionary denial factors may influence litigation strategies, while reviewing their internal procedures to help ensure compliance with strict RPI identification rules at the time of filing.