PTAB challenges

Proceedings overview

There is one AIA trial proceeding on US patent 9448367, which resulted in a discretionary denial. This outcome means the patent claims were not reviewed on the merits and remain in their original form, providing less certainty for a defendant.

IPR2026-00019 — Accelight Technologies, Inc. et al. v. I-Lung HO et al

• Type: Inter Partes Review
• Filed: 2025-10-10
• Status: Discretionary Denial
• Judge panel: Not publicly available yet for this procedural stage.
• Petition grounds: Not publicly available in the provided information.
• Institution decision: Denied (Discretionary Denial) — 2026-03-06. The PTAB exercised its discretion to deny institution of the IPR. The specific reasoning for the discretionary denial is not provided in the prompt but typically relates to factors such as parallel district court litigation, settlement negotiations, or other considerations under 35 U.S.C. § 314(a).
• Final Written Decision: Not issued, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: No Federal Circuit appeal on an institution denial is indicated in the provided information.
• Defensive value: The patent owner prevailed at the institution stage, meaning all claims challenged in this IPR remain presumptively valid. An IPR-based defense on the same grounds may be more challenging in the future, as the PTAB has already exercised its discretion against review.

Strategic summary

All claims of US9448367 are currently SUSTAINED, as the single IPR filed against it was denied institution. There have been no claims invalidated or narrowed through PTAB proceedings.

Regarding the estoppel landscape, since institution was denied in IPR2026-00019, the petitioner (Accelight Technologies, Inc. et al.) and its privies may be estopped under 35 U.S.C. § 315(e)(2) from asserting in future district court or ITC proceedings any ground that was raised or reasonably could have been raised in the petition. However, without the specifics of the petition grounds, it is difficult to determine precisely which prior-art grounds are still available to a potential defendant.

There is no discernible pattern of multiple IPRs filed by the same petitioner, nor aggressive PTAB appeals by the patent owner based on the single proceeding. Unified Patents is not indicated as being in the chain for this proceeding.

Recommended next steps

Since IPR2026-00019 resulted in a discretionary denial, all claims of US9448367 remain in force. A defendant facing assertion of this patent should be aware that the PTAB has opted not to review the claims on the merits in the single challenge filed to date. The decision for the discretionary denial of IPR2026-00019 was issued on 2026-03-06. More details on the PTAB's reasoning would be available in the institution decision, which can be found on the USPTO PTAB Decisions portal (https://ptab.uspto.gov/#/search/decisions).