PTAB challenges

Proceedings overview

One AIA trial proceeding is on file for US patent 10933370, which resulted in a discretionary denial of institution. This outcome means the patent's claims have not undergone a full merits review at the PTAB, suggesting the patent has not been substantively challenged and its claims remain intact.

IPR2025-01324 — UNION ELECTRIC COMPANY et al. v. Birchtech Corp.

• Type: Inter Partes Review
• Filed: 2025-07-18
• Status: Discretionary Denial. This indicates that the Patent Trial and Appeal Board (PTAB) chose not to institute an inter partes review trial, likely based on procedural or policy considerations, rather than a comprehensive review of the patentability merits. The proceeding was officially terminated on 2025-11-20.
• Judge panel: The institution decision was likely issued by the Director of the USPTO, John Squires. Around the time of this decision (late 2025), the Director had taken personal control over institution decisions, often issuing summary denials without specifying a panel of Administrative Patent Judges.
• Petition grounds: Specific claims challenged, prior art cited, and the statutory bases (§ 102 / § 103 / § 112) for the challenge are not publicly detailed in the context of a discretionary denial.
• Institution decision: Denied on 2025-11-20. The denial was procedural, consistent with a broader trend at the PTAB at that time to deny institution on discretionary grounds, often citing factors like parallel district court litigation, proximity of trial dates, or policies concerning multiple petitions.
• Final Written Decision (if issued): Not applicable, as institution of the trial was denied.
• Settlement / termination: The proceeding terminated with the denial of institution on 2025-11-20.
• Appeal: Institution decisions are generally final and non-appealable.
• Defensive value: For a defendant, this means that the claims of US10933370 have not been invalidated by the PTAB through this proceeding. While the specific grounds raised by UNION ELECTRIC COMPANY et al. (and their privies) may be estopped in future proceedings or litigation, the scope of estoppel from a discretionary denial is typically narrower than from a full merits review.

Strategic summary

All claims of US10933370 remain UNTESTED by the PTAB on their merits, as the single inter partes review proceeding (IPR2025-01324) resulted in a discretionary denial of institution. No claims have been canceled or formally sustained through a Final Written Decision.

The estoppel landscape for IPR2025-01324 is that UNION ELECTRIC COMPANY et al. and their privies may be estopped from asserting the specific prior-art grounds raised in their petition in subsequent litigation or PTAB proceedings, pursuant to 35 U.S.C. § 315(e)(2). However, because institution was denied on discretionary grounds rather than a decision on the merits, the breadth of this estoppel can be a complex legal question, potentially leaving other, non-raised prior-art grounds open. Other non-privy defendants are generally not affected by this estoppel.

The pattern signals indicate that this denial occurred during a period (late 2025) when USPTO Director John Squires frequently issued summary discretionary denials, often without extensive explanation, potentially to manage the PTAB's caseload or to address concerns about parallel litigation. Birchtech Corp. is an active patent owner, known for its intellectual property portfolio in activated carbon technologies and has been involved in multiple patent infringement lawsuits, securing settlements and significant verdicts. The denial of this IPR petition suggests a strategy by the patent owner to defend its patents against PTAB challenges, or reflects a broader PTAB policy favoring such denials in certain contexts, rather than a definitive test of the patent's validity.

Recommended next steps

As a defendant facing assertion of US10933370 today, it is crucial to recognize that no claims of this patent have been invalidated by the PTAB. The discretionary denial of IPR2025-01324 means that the patent's claims have not undergone a substantive validity review at the PTAB. Any consideration of a new IPR challenge should include a thorough analysis of the specific grounds for the discretionary denial in IPR2025-01324, an assessment of the current PTAB discretionary denial policies (such as the Fintiv factors), and a strategy to present new prior art or distinct non-estoppeled grounds that might overcome these policies, especially if there is ongoing parallel district court litigation.