PTAB challenges

Proceedings Overview

U.S. Patent 8,438,120 has been challenged in one Inter Partes Review (IPR) proceeding, IPR2026-00304, which is currently pending. Due to its early stage, no claims have been invalidated or sustained by the PTAB yet. This means the patent remains fully asserted, and its claims are currently untested by a final written decision.

IPR2026-00304 — Google LLC v. K Mizra LLC

• Type: Inter Partes Review
• Filed: 2026-03-31
• Status: Pending. The proceeding was last modified on 2026-05-06, indicating it is active and has not yet reached an institution decision or final judgment.
• Judge panel: The judge panel information is not publicly available at this early stage of the proceeding.
• Petition grounds: The specific claims challenged and the prior art cited in Google LLC's petition for IPR2026-00304 are not yet publicly detailed in the provided information or easily accessible through general search at this early stage.
• Institution decision: An institution decision has not yet been issued. The statutory deadline for the PTAB to issue an institution decision is typically one year from the filing date of the petition, which would be around March 31, 2027.
• Final Written Decision: Not issued, as the proceeding is still pending.
• Settlement / termination: Not applicable, as the proceeding is pending.
• Appeal: Not applicable, as no final decision has been rendered.
• Defensive value: As this IPR is in its nascent stages, it currently offers minimal direct defensive value regarding claim validity. However, it indicates that Google LLC is actively challenging the patent, which could lead to claims being invalidated or narrowed in the future. Parties facing assertion may want to monitor this proceeding closely.

Strategic Summary

Currently, all claims of US 8,438,120 remain UNTESTED by a Final Written Decision from the PTAB. There are no claims that have been canceled or definitively sustained through an IPR.

The estoppel landscape is not yet established for this patent. Since no institution decision has been rendered for IPR2026-00304, 35 U.S.C. § 315(e)(2) estoppel, which bars petitioners and their privies from raising grounds they raised or reasonably could have raised, has not come into effect. Therefore, all prior-art grounds are theoretically still available for other potential challengers.

Regarding pattern signals, only one IPR has been filed against this patent, initiated by Google LLC. This suggests a targeted challenge rather than a broad campaign by multiple petitioners or a defensive aggregator at this time. The patent owner, K Mizra LLC, has not yet had to pursue PTAB appeals related to this patent, given the early stage of the sole IPR.

Recommended Next Steps

For a defendant currently being asserted against, the key next step is to monitor IPR2026-00304 closely. The most critical upcoming milestone for this proceeding will be the institution decision deadline (around March 31, 2027). This decision will indicate whether the PTAB believes Google LLC has demonstrated a reasonable likelihood of prevailing on at least one challenged claim, thus allowing the trial to proceed. If the IPR is instituted, the patent's claims will face substantive review.