PTAB challenges

Proceedings overview

There is one AIA trial proceeding on file for US Patent 11878049. This proceeding is currently pending, meaning no claims have been invalidated or sustained by a final PTAB decision. The patent's claims remain untested by an AIA trial.

IPR2026-00351 — Apotex Inc et al. v. Agios Pharmaceuticals Inc

• Type: Inter Partes Review
• Filed: 2026-05-18
• Status: Pending. The petition has been filed, and the proceeding is in its early stages before a decision on institution.
• Judge panel: Not yet publicly assigned or determined at this early stage.
• Petition grounds: Not yet publicly available as the petition details are typically released after a filing receipt is issued and the case progresses.
• Institution decision: Not yet issued. A decision on institution is expected within approximately six months from the filing of the petition.
• Final Written Decision: Not yet issued. If the petition is instituted, a Final Written Decision would be due approximately one year from the institution date.
• Settlement / termination: No settlement or termination has occurred.
• Appeal: No appeal has occurred as no Final Written Decision has been issued.
• Defensive value: This proceeding indicates that at least one party (Apotex Inc. et al.) is challenging the patent. However, as it is in the very early stages, it currently offers no definitive defensive value regarding claim validity. Defendants should monitor its progress closely.

Strategic summary

Currently, all claims of US11878049 are UNTESTED by a final PTAB decision. The single Inter Partes Review (IPR2026-00351) was filed on 2026-05-18 and is in its nascent stages, with no institution decision yet rendered. Therefore, no claims have been canceled, sustained, or modified through PTAB trials.

Regarding the estoppel landscape, since no institution decision or final written decision has occurred, the estoppel provisions of 35 U.S.C. § 315(e)(2) are not yet applicable. This means that, for a defendant facing assertion of this patent, prior-art grounds are generally still available for future challenges, subject to the outcome of IPR2026-00351.

There are no apparent pattern signals yet, such as multiple IPRs from the same petitioner or aggressive PTAB appeals by the patent owner, given that this is the first and only proceeding filed to date on this patent.

Recommended next steps

As IPR2026-00351 is pending, a defendant should closely monitor its progress. Key milestones to track include:

• The Patent Owner's preliminary response deadline.
• The institution decision deadline (approximately 2026-11-18, six months from the petition filing date, assuming no extensions).
• If instituted, the subsequent trial schedule, including any oral hearings and the eventual Final Written Decision due date (approximately one year from institution).

The absence of prior PTAB activity means that the patent's claims have not been subjected to the scrutiny of AIA trials before this filing.