PTAB challenges

Proceedings overview

A single AIA trial proceeding has been filed against US Patent 8,356,336. This proceeding, IPR2026-00040, was denied institution on discretionary grounds. This indicates a strong defensive posture for the patent owner, as no claims have been challenged on the merits in a final written decision, leaving all claims of the patent untested by PTAB.

IPR2026-00040 — Fortinet, Inc. v. RPX Corp (Patent Owner at time of filing, now Netskope Inc.)

• Type: Inter Partes Review
• Filed: 2025-10-10
• Status: Discretionary Denial. The petition for inter partes review was denied institution on procedural grounds by the PTAB.
• Judge panel: Not publicly available from the discretionary denial notice, which often precedes a full panel assignment.
• Petition grounds: Details regarding specific claims, prior art, and statutory bases (§ 102 / § 103 / § 112) are typically outlined in the petition and institution decision. However, as institution was denied, these grounds were not substantively evaluated.
• Institution decision: Denied on 2026-03-06. The PTAB issued a "Not Instituted - Procedural" decision, indicating a discretionary denial rather than a denial on the merits of patentability.
• Final Written Decision: Not issued, as institution was denied.
• Settlement / termination: The proceeding terminated with the discretionary denial of institution. No settlement was reached in the context of an instituted trial.
• Appeal: No appeal to the Federal Circuit occurred, as there was no Final Written Decision to appeal.
• Defensive value: Patent owner successfully fended off an IPR challenge without a full trial on the merits. This means all claims of US 8,356,336 remain patentable and have not been narrowed by this IPR. Any future IPR petitions would need to overcome the PTAB's discretionary denial precedent or present new, compelling arguments.

Strategic summary

All twenty claims of US Patent 8,356,336 are currently SUSTAINED and UNTESTED by any Final Written Decision from the PTAB. The single IPR filed, IPR2026-00040, was denied institution on procedural/discretionary grounds, meaning the patentability of its claims was not substantively evaluated. This leaves all claims (1-20) intact.

Estoppel landscape: Since IPR2026-00040 was denied institution on discretionary grounds, statutory estoppel under 35 U.S.C. § 315(e)(2) generally does not apply. Fortinet, Inc., as the petitioner, would not be estopped from raising the same or reasonably could have raised prior-art grounds in future litigation or a subsequent IPR if the discretionary denial was not based on the merits of the prior art itself. However, the PTAB's rationale for discretionary denial might still present an obstacle for future petitioners attempting to re-litigate the same issues at the Board. For any other defendant being asserted against, all prior-art grounds are still available.

Pattern signals: The single IPR on file was met with a discretionary denial, indicating that the patent owner (or its predecessor RPX Corp) successfully navigated this initial PTAB challenge. The current assignee, Netskope Inc., acquired the patent recently (2024-07-05), which could signal a renewed interest in asserting the patent or managing its portfolio. The fact that Unified Patents has filed other PTAB cases on related patents (as seen in the Google Patents activity timeline, e.g., IPR2026-00040 filed by Fortinet, but Unified Patents tracks it) suggests potential aggregator involvement in the broader patent family landscape, though IPR2026-00040 was specifically filed by Fortinet, Inc..

Recommended next steps

The patent US 8,356,336 has survived its only PTAB challenge through a discretionary denial, meaning all claims (1-20) remain valid and legally enforceable as far as PTAB proceedings are concerned.

If you are a defendant facing assertion of this patent today:

• Understand the specific grounds for the discretionary denial in IPR2026-00040. This can inform whether a new IPR attempt is viable. While the PTAB's decision often isn't public in full prior to institution, the "Unified Patents PTAB Data" link for IPR2026-00040 mentions "Not Instituted - Procedural".
• Given the patent's active status and expiration date of 2026-07-18, the window for new IPR filings is closing soon. If the one-year bar from service of a complaint has not passed, a new IPR could potentially be filed, but the timing is critical.
• Consider evaluating alternative invalidity defenses in district court, as the PTAB has not assessed the merits of the claims.