PTAB challenges

Proceedings overview

Two AIA trial proceedings have been filed against US patent 12298313. One proceeding (IPR2026-00166) was terminated, and the other (IPR2026-00270) is currently pending. This indicates the patent is actively being challenged by a defendant, Sarepta Therapeutics, Inc. et al.

IPR2026-00270 — Sarepta Therapeutics, Inc. et al. v. Genzyme Corp

• Type: Inter Partes Review
• Filed: 2026-02-26
• Status: Pending (The proceeding is ongoing and has not yet reached a final decision regarding institution or merits).
• Judge panel: Not yet publicly available.
• Petition grounds: Specific claims, prior art, and statutory bases (§ 102 / § 103) are not yet publicly available through standard PTAB search interfaces for this pending case.
• Institution decision: Not yet issued. The PTAB has a statutory deadline of 6 months from the filing date to decide on institution. For a petition filed on 2026-02-26, the institution decision is due around 2026-08-26.
• Final Written Decision: Not applicable; the proceeding is pending.
• Settlement / termination: Not applicable; the proceeding is pending.
• Appeal: Not applicable; the proceeding is pending.
• Defensive value: This active IPR means that at least some claims of US12298313 are currently under review for patentability. The outcome of the institution decision, due around August 2026, will significantly impact the patent's defensive posture. If instituted, the claims will be subject to a full trial.

IPR2026-00166 — Sarepta Therapeutics, Inc. et al. v. Genzyme Corp

• Type: Inter Partes Review
• Filed: 2025-12-02
• Status: Terminated (This proceeding concluded without a final decision on the merits, likely due to settlement or petitioner request before institution or FWD).
• Judge panel: Not publicly available.
• Petition grounds: Specific claims, prior art, and statutory bases (§ 102 / § 103) are not publicly available without access to the full petition.
• Institution decision: An institution decision was not reached because the proceeding was terminated prior to institution.
• Final Written Decision: Not applicable; the proceeding was terminated.
• Settlement / termination: The proceeding was terminated on 2026-04-25. The specific terms of termination or settlement are typically confidential and not publicly available.
• Appeal: Not applicable; the proceeding was terminated before a Final Written Decision.
• Defensive value: The termination of this IPR suggests that the patent owner, Genzyme Corp, either settled with Sarepta Therapeutics, Inc. et al. or that Sarepta chose to withdraw its petition for other reasons. While the claims were not invalidated, the termination of an IPR before institution can sometimes indicate that the petitioner chose not to pursue it further, or a confidential agreement was reached. For a defendant, this means the claims challenged in this IPR were not judicially tested, and their patentability remains undeterred by this specific proceeding.

Strategic summary

Currently, the patent US12298313 has not had any claims canceled or sustained through a Final Written Decision at the PTAB. IPR2026-00166 was terminated, meaning no claims were formally adjudicated. IPR2026-00270 is pending, and its institution decision is expected around August 2026. Therefore, all claims of US12298313 remain untested by a PTAB Final Written Decision.

The estoppel landscape is important. Since Sarepta Therapeutics, Inc. et al. was the petitioner in both IPRs, they (and their privies) would be barred under § 315(e)(2) from raising any ground they raised or reasonably could have raised in IPR2026-00166, which was terminated. However, since IPR2026-00166 was terminated before institution, statutory estoppel under § 315(e)(1) and § 315(e)(2) does not apply. The estoppel effects of IPR2026-00270 will depend on its outcome (institution or FWD). For other defendants, prior art grounds remain available for challenge.

The pattern of having the same petitioner, Sarepta Therapeutics, Inc. et al., file two IPRs on this patent within a few months signals a concerted effort to challenge the patent's validity. One IPR was terminated, which could suggest a confidential settlement or strategic shift, while another is actively pending. The fact that the patent was granted recently (2025-05-13) and already faces two IPR challenges indicates that it is considered a significant barrier by at least one market player.

Recommended next steps

Given the pending IPR2026-00270, a defendant facing assertion of US12298313 should:

• Monitor the institution decision for IPR2026-00270, expected around 2026-08-26. This decision will be crucial as it will determine whether the claims proceed to a full trial at the PTAB. Information regarding this proceeding can be found on the USPTO PTAB E2E portal.
• If the claims are instituted, follow the progress of the trial, including any oral hearings and the eventual Final Written Decision, which would be due approximately one year after institution.
• Consider the grounds raised in IPR2026-00270 (once public) to assess if there are alternative or stronger prior art arguments that could be presented in a separate IPR, especially if not overlapping with the terminated IPR.
• Investigate the reasons for the termination of IPR2026-00166, as this may provide insights into Sarepta's strategy or any potential settlement with the patent owner. This information is typically confidential, but the existence of a settlement may be inferred.