PTAB challenges

Proceedings overview

Two AIA trial proceedings have been filed against US patent 10980901. One IPR (IPR2023-00551) has settled, and another (IPR2025-01582) is currently pending. The patent owner successfully navigated the first IPR without a final written decision on the merits, indicating a resilient patent, while the second IPR's outcome is still uncertain.

IPR2025-01582 — Curium US LLC v. European Atomic Energy Community Euratom, Universitaet Heidelberg

• Type: Inter Partes Review
• Filed: 2025-09-26
• Status: Pending. The proceeding is active and awaiting further developments.
• Judge panel: Not publicly available yet.
• Petition grounds: Not publicly available yet.
• Institution decision: Not yet issued.
• Final Written Decision (if issued): Not applicable.
• Settlement / termination: Not applicable.
• Appeal: Not applicable.
• Defensive value: This active IPR means that the validity of US10980901 is currently being challenged. The outcome could significantly impact the defensive posture for potential defendants.

IPR2023-00551 — Fusion Pharmaceuticals, Inc. v. European Atomic Energy Community Euratom, Universitaet Heidelberg

• Type: Inter Partes Review
• Filed: 2023-03-14
• Status: Settlement. The parties reached a settlement.
• Judge panel: Not publicly available.
• Petition grounds: Not publicly available.
• Institution decision: Not publicly available.
• Final Written Decision (if issued): Not applicable, as the case settled.
• Settlement / termination: The proceeding was terminated due to a settlement between Fusion Pharmaceuticals, Inc. and the patent owner. The terms of the settlement are confidential. The effective date of the settlement was 2023-02-13.
• Appeal: Not applicable.
• Defensive value: The settlement of this IPR means that no claims of US10980901 were invalidated by a Final Written Decision from the PTAB. This outcome generally strengthens the patent's standing, as a challenger initiated a review but did not pursue it to a final judgment on validity.

Strategic summary

The claims of US10980901 currently remain SUSTAINED or UNTESTED through PTAB proceedings, as no Final Written Decisions have resulted in claim cancellation. IPR2023-00551 was terminated due to a settlement, meaning the patent owner successfully avoided a merits-based decision on the challenged claims. This indicates a certain resilience of the patent in the face of initial challenges.

Regarding the estoppel landscape, § 315(e)(2) estoppel from IPR2023-00551 would apply to Fusion Pharmaceuticals, Inc. (and its privies) for any grounds raised or that reasonably could have been raised in that petition. For other defendants facing assertion of US10980901, the prior art grounds that could have been raised in IPR2023-00551 are likely still available unless they are in privy with Fusion Pharmaceuticals, Inc. The active IPR2025-01582 by Curium US LLC is a new challenge, and its outcome will determine the future estoppel landscape for that petitioner and any potential privies. The current situation suggests that other parties are still actively seeking to challenge the patent.

There is no apparent pattern of the same petitioner filing multiple IPRs on this patent. While the patent owner settled one IPR, indicating a willingness to resolve disputes, the ongoing IPR suggests continued efforts to assert the patent or that new challenges are emerging from different entities. The lack of a Final Written Decision in the settled IPR means there hasn't been a PTAB determination on the merits that the patent owner has had to appeal.

Recommended next steps

For IPR2025-01582, as the proceeding is pending, it is crucial to monitor the trial-stage milestones, specifically the institution decision deadline. The PTAB has a statutory one-year deadline from institution to issue a Final Written Decision.