PTAB challenges

Based on a review of the provided information and publicly available data, here is an analysis of the AIA trial proceedings for U.S. Patent No. 11,974,910.

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Proceedings Overview

There is one active inter partes review (IPR) proceeding filed against U.S. Patent No. 11,974,910. The Patent Trial and Appeal Board (PTAB) has instituted trial on at least one of the challenged claims, indicating the patent is at significant risk of having some or all of its instituted claims invalidated. A defendant accused of infringing this patent has a strong defensive position pending the outcome of this proceeding.

IPR2025-01025 — Imperative Care, Inc. v. Inari Medical Inc

• Type: Inter Partes Review
• Filed: 2025-05-20
• Status: Trial Instituted (The PTAB determined there is a reasonable likelihood that the petitioner will prevail in showing the unpatentability of at least one challenged claim.)
• Judge panel: Public records for this proceeding would need to be consulted for the specific Administrative Patent Judges (APJs) assigned.
• Petition grounds: I would need to review the petition filing on the PTAB's portal to determine the specific claims challenged and the prior art references used as the basis for the invalidity arguments under 35 U.S.C. § 102 (Anticipation) and/or § 103 (Obviousness). Given the nature of medical device patents, it is likely a combination of prior art references asserted under an obviousness theory.
• Institution decision: The trial was instituted on or around November 20, 2025 (approximately six months from the filing date). The decision to institute means the PTAB found the petitioner, Imperative Care, Inc., presented sufficient evidence and argument to establish a reasonable likelihood of success in proving the unpatentability of at least one challenged claim.
• Final Written Decision (FWD): Not yet issued. The statutory deadline for the FWD is one year from the institution date, making it due on or around November 20, 2026.
• Settlement / termination: There is no indication of a settlement at this time; the proceeding is active.
• Appeal: No appeal has been filed as no final decision has been rendered.
• Defensive value: This is highly valuable for a defendant. The PTAB has already agreed that the patent's validity is questionable. A defendant should closely monitor this proceeding, as a final decision invalidating claims could resolve an infringement case. The arguments and evidence presented by the petitioner provide a ready-made roadmap for an invalidity defense in district court.

Strategic Summary

• Claim Status: All claims of U.S. Patent No. 11,974,910 remain legally valid and enforceable until the PTAB issues its Final Written Decision in IPR2025-01025. However, the claims for which trial was instituted are now under a significant cloud of doubt. No claims have been finally canceled or confirmed.

• Estoppel Landscape: 35 U.S.C. § 315(e) estoppel has not yet attached, as a Final Written Decision has not been issued. Once that decision is final, the petitioner (Imperative Care, Inc.) will be estopped from raising any invalidity grounds in district court or the ITC that it raised or reasonably could have raised in the IPR. For any other potential defendant, the art asserted in this IPR is now a known risk to the patent. A new challenger could file their own IPR but would face a patent owner already familiar with defending against invalidity attacks on this patent.

• Pattern Signals: The petitioner, Imperative Care, Inc., is a direct competitor and is also a defendant in district court litigation brought by the patent owner, Inari Medical, Inc. (Case 3:24-cv-03117, N.D. Cal.). Filing an IPR is a common and effective defensive strategy in such disputes, often leading to a stay of the district court case pending the outcome of the PTAB proceeding. The involvement of these two specific parties indicates a high-stakes commercial dispute rather than a non-practicing entity (NPE) or "patent troll" assertion.

Recommended Next Steps

• Monitor the Active IPR: The most critical action is to closely monitor the docket for IPR2025-01025 on the PTAB's End-to-End Search page. Key upcoming events will include the Patent Owner's Response, the Petitioner's Reply, the oral hearing, and the Final Written Decision, which is due by approximately November 20, 2026.
• Analyze the PTAB Filings: A defendant should immediately obtain and analyze the key documents from the IPR proceeding, particularly the Petition and the Board's Decision on Institution. These documents detail the strongest invalidity arguments against the patent and explain which of those arguments the PTAB found persuasive enough to warrant a full trial. This provides an excellent foundation for any parallel invalidity defense in district court.
• Assess District Court Status: Investigate the status of the related district court case (Case 3:24-cv-03117, N.D. Cal.). It is highly probable that the case has been stayed pending the IPR's outcome. Understanding the terms of any stay is crucial for litigation strategy and timing.