PTAB challenges

Proceedings overview

A single AIA trial proceeding, PGR2025-00009, has been filed against US patent 12123035. This proceeding has reached a Final Written Decision status. However, the specific claim-level outcomes and reasoning from this decision are not publicly available in the search results at this time. This leaves a defendant in a position where the outcome of this PGR is known to be a Final Written Decision, but its specific impact on the patent's claims is currently undetermined based on available public information.

PGR2025-00009 — Merck Sharp & Dohme LLC v. Halozyme, Inc. et al.

• Type: Post-Grant Review
• Filed: 2024-12-27
• Status: Final Written Decision, last modified 2026-06-24. While the proceeding has reached a Final Written Decision, the specific details of the decision, including claim-level outcomes, are not yet publicly available in the provided search results.
• Judge panel: Administrative Patent Judges Cynthia M. Hardman, Jeffrey N. Fredman, and Susan L. C. Mitchell.
• Petition grounds: The exact claims and statutory bases (e.g., § 102 / § 103 / § 112) challenged in the petition for US12123035 are not specified in the public search results, beyond a general indication that Merck has challenged Halozyme's patents related to modified PH20 hyaluronidase polypeptides in multiple PGRs.
• Institution decision: The petition was instituted on 2025-07-11. The panel's specific reasoning for institution regarding US12123035 is not publicly detailed in the search results.
• Final Written Decision (if issued): As per the provided information, a Final Written Decision was issued, with a last modification date of 2026-06-24. However, the claim-level verdict (e.g., which claims were canceled or held patentable, and the panel's reasoning) for US12123035 in PGR2025-00009 is not publicly available in the search results at this time. News articles discussing FWDs involving Merck and Halozyme refer to other patent numbers (e.g., US11952600 and US12018298) being invalidated.
• Settlement / termination: There is no public information indicating a settlement or termination of this specific proceeding other than the issuance of a Final Written Decision.
• Appeal: Information regarding a Federal Circuit appeal for PGR2025-00009 on US12123035 is not publicly available in the search results.
• Defensive value: The status of a Final Written Decision means the PTAB has rendered a final judgment on the patentability of the challenged claims. However, without the details of the decision, the precise defensive value for someone facing assertion of this patent remains unknown. If claims were invalidated, it would significantly weaken any infringement theory built upon them. Conversely, if claims were sustained, it would suggest a hardened patent against these specific challenges.

Strategic summary

Currently, only one PTAB proceeding, PGR2025-00009, has been identified for US patent 12123035. This proceeding has reached the stage of a Final Written Decision, but the specific details of this decision, including which claims were canceled, sustained, or left untested, are not publicly available through the search conducted. Therefore, a clear picture of the patent's claim status (CANCELED vs. SUSTAINED vs. UNTESTED) cannot be definitively provided.

The estoppel landscape under § 315(e)(2) will depend heavily on the outcome of the Final Written Decision in PGR2025-00009. Once the FWD is published, Merck Sharp & Dohme LLC (and its privies) would be barred from raising any ground they raised or reasonably could have raised during this PGR. Without knowing the grounds or claims addressed, it's impossible to determine which prior-art grounds remain available to others. There is a pattern of Merck Sharp & Dohme LLC filing multiple PGRs against Halozyme's MDASE-related patents, with some resulting in invalidations for other patents. This indicates an aggressive strategy by Merck against Halozyme's portfolio.

Recommended next steps

Given that a Final Written Decision has been issued for PGR2025-00009 on US12123035, the immediate next step for a defendant would be to obtain and review the full text of this decision. This FWD, once publicly available, would detail the PTAB's findings regarding the patentability of the challenged claims. As of this analysis, the specific content of the FWD for PGR2025-00009 on US12123035 is not available in the public search results. While other related Halozyme patents have seen invalidations in separate PGRs, the outcome for US12123035 remains to be concretely determined from the public record. Continuously monitor the USPTO PTAB E2E portal for the publication of the Final Written Decision for PGR2025-00009, as its disposition will critically inform any defensive strategy.