USPTO Designates RPI Case as Informative
Curium case addresses 'Real Parties in Interest'
The United States Patent and Trademark Office recently issued critical guidance regarding the procedural consequences of amending mandatory notices in inter partes review (IPR) proceedings. The Director designated a February 2026 order as an informative decision.
This designation “provides Board norms on recurring issues” and offers authoritative direction for patent practitioners. The dispute centers on the legal effect of updating a petition to name additional corporate entities weeks after the initial filing date.
The Director concluded this action mandates a new filing date, triggering a cascade of procedural resets. The decision is Curium US LLC v. Universität Heidelberg and The European Atomic Energy Community (EURATOM), IPR2025-01582, Paper 11 (PTAB Feb. 25, 2026).
The order confirms there is a strict penalty for incomplete corporate disclosures at the institution phase.
Background of the Dispute
The underlying conflict involves international corporate interests and high-value patented technology. On September 26, 2025, Curium US LLC filed a petition challenging U.S. Patent No. 10,980,901. The patent covers technology developed by Universität Heidelberg and EURATOM, represented by the European Commission.
In the initial inter partes review (IPR) filing, the petitioner identified “only itself as the real party-in-interest” (Curium, p. 2). The Board issued a Notice of Filing Date Accorded on October 3, 2025, proceeding under the standard assumption that the mandatory disclosures were complete and accurate.
The patent owner responded with a targeted request for discretionary denial, launching a factual attack on the petitioner’s corporate isolation. The patent owner argued the petitioner “is owned and controlled by Curium US Holdings LLC and France-based Curium Pharma, all of which share offices at 111 Westport Plz. Dr., St. Louis, MO, and have an interest in the patented technology” (Curium, p. 2).
The patent owner contended these parent organizations direct the petition and control the litigation strategy. The patent owner insisted these global entities benefit directly from the proceeding. The patent owner concluded this omission violated statutory requirements and justified denying institution entirely (Curium, p. 2).
The petitioner resisted the characterization of its parent companies and international affiliates as real parties in interest. The petitioner argued it “does not believe Curium US Holdings LLC (or other entity) is an RPI” and maintained it “represents only its own interest in this IPR proceeding” (Curium, p. 2).
The petitioner chose a pragmatic administrative route rather than litigating the complex corporate relationship. The petitioner submitted an “updated mandatory notice naming Curium US Holdings LLC and its direct parent, Curium Netherlands BV” on January 5, 2026 (Curium, p. 2).
The petitioner stated this filing was intended “to moot this issue” rather than serve as an admission of corporate control (Curium, p. 2). The petitioner argued the updated notice fulfilled the statutory requirements without necessitating any change to the original September filing date.
Analysis
The central legal conflict required the Director to determine the precise procedural effect of an amended mandatory notice on an already-accorded filing date.
The statute governing inter partes review, 35 U.S.C. § 312(a)(2), imposes rigid requirements for administrative petitions. The statute allows the Board to consider a petition “only if... the petition identifies all real parties in interest” (Curium, p. 3).
The Board relies on accurate real party in interest disclosures to apply statutory estoppel provisions and prevent related entities from filing repetitive, harassing challenges against the same patent.
The Director evaluated the petitioner’s January update against established Board precedent to resolve the dispute. The Director relied heavily on the precedential case Corning Optical Communications RF, LLC v. PPC Broadband Inc., which dictates that “any Petition corrected to disclose additional RPIs must be given a new filing date” (Curium, p. 3).
The Director held the petitioner’s updated notice satisfied the statutory disclosure requirement but triggered an automatic, mandatory reset of the filing timeline.
The Director articulated the rationale clearly:
Petitioner’s amendment of its RPI disclosures results in according the Petition a new filing date. Petitioner’s updated mandatory notice appears to meet the statutory requirement to name all RPIs. 35 U.S.C. § 312(a)(2). Further, unlike Corning Optical, according a new filing date to the Petition does not implicate a time-bar under 35 U.S.C. § 315(b) that requires terminating the proceeding. ...
Thus, the Petition shall be accorded a new filing date of January 5, 2026-the filing date of Petitioner’s updated mandatory notice (Curium, p. 3).
The Director “accorded a petition a new filing date after the petitioner updated its mandatory notices to identify new real parties in interest” (Announcement). The Director implemented a severe procedural consequence for the initial omission.
The Director ordered that the “Patent Owner’s Brief Requesting Discretionary Denial of Institution (Paper 5), Petitioner’s Opposition to Patent Owner’s discretionary denial brief (Paper 7), and Patent Owner’s Preliminary Response (Paper 8), and all accompanying exhibits, shall be expunged from the record” (Curium, p. 4).
Key Takeaways and Practical Implications
This informative decision provides essential “guidance on Board rules and practices” governing corporate disclosures.
Patent practitioners face strict, unforgiving requirements regarding real party-in-interest identifications. A failure to identify every relevant corporate entity threatens the timeline of an entire proceeding. The strategy of waiting to amend a mandatory notice until prompted by a patent owner carries severe administrative and financial risks.
The petitioner in this specific dispute avoided total dismissal by a narrow margin. The new January 5, 2026 filing date did not trigger the statutory one-year time bar under 35 U.S.C. § 315(b).
Had the petitioner been served with a complaint alleging patent infringement more than a year prior to January 5, 2026, the Director’s reset of the filing date would have forced a mandatory termination of the inter partes review.
Practitioners representing corporate subsidiaries must conduct exhaustive pre-filing investigations to identify all parent companies, funding sources, and controlling entities. Erring on the side of over-disclosure in the initial petition protects the filing date and shields the client from catastrophic dismissals.
Patent owners gain a clear tactical advantage from this ruling. Challenging a petitioner’s real party in interest disclosure serves as a highly effective defensive tool. A successful challenge forces the petitioner into a difficult, high-stakes position. The petitioner must choose between litigating the corporate relationship or amending the mandatory notice to include the parent companies. Amending the notice results in a lost filing date.
The expungement of the preliminary response and discretionary denial briefs erases months of expensive, time-consuming legal work. Both parties must reinvest significant resources to draft entirely new filings based on the adjusted schedule.
This dynamic encourages patent owners to scrutinize the global corporate structure of any challenger aggressively. Seeking out international parent companies, shared office spaces, and overlapping boards of directors provides rich material for discretionary denial requests.
The risk of expungement changes the calculus for both sides of the PTAB dispute. Petitioners lose the benefit of early briefing and face extended periods of uncertainty.
Patent owners force delays that keep their issued patents valid, enforceable, and capable of generating licensing revenue for longer periods.
Conclusion
The Director’s order in Curium v. Universität Heidelberg enforces rigid adherence to statutory disclosure requirements. The Board demands absolute transparency regarding the entities funding, directing, or benefiting from a patent challenge. An informative decision serves to guide future Board panels and practitioners alike, establishing clear “Board norms on recurring issues” within the tribunal.
This strict procedural enforcement aligns with Director John A. Squires’ apparent pro-patent stance, aimed at increasing the value of in-force patents and narrowing the scope of Board challenges.
Recent initiatives under his leadership include assuming personal control over institution decisions to limit post-grant reviews and reversing previous Board decisions that invalidated https://blog.patentriff.com/p/uspto-codifies-desjardins-new-mpep.
Practitioners must prioritize comprehensive corporate disclosures before finalizing any PTAB filing. The administrative penalty for an incomplete disclosure involves wasted legal fees, delayed adjudications, and the severe potential for complete dismissal under statutory time bars.
The patent system operates on strict jurisdictional timelines.
Patent owners will aggressively leverage corporate omissions to disrupt and derail challenges. The intellectual property sector demands cautious, pragmatic, and risk-averse strategies to protect technological innovation and manage administrative vulnerabilities.
This decision, and its designation as informative, reinforces the absolute necessity of thorough preparation and corporate transparency in patent trials.
Disclaimer: This is provided for informational purposes only and does not constitute legal or financial advice. To the extent there are any opinions in this article, they are the author’s alone and do not represent the beliefs of his firm or clients. The strategies expressed are purely speculation based on publicly available information. The information expressed is subject to change at any time and should be checked for completeness, accuracy and current applicability. For advice, consult a suitably licensed attorney and/or patent professional.