PTAB challenges

Proceedings overview

One AIA trial proceeding has been filed against US patent 12264345, which is currently active and in the "Trial Instituted" phase. This gives a defendant a posture where certain claims are currently under review for patentability, but no final decision on invalidation or patentability has been issued yet.

PGR2025-00052 — Merck Sharp & Dohme LLC v. Halozyme Inc

• Type: Post-Grant Review
• Filed: 2025-06-27
• Status: Trial Instituted – The PTAB has decided to initiate a trial to review the patentability of the challenged claims. As of 2026-05-14, the proceeding was last modified and the trial is ongoing.
• Judge panel: Information regarding the specific Administrative Patent Judges (APJs) on the panel for PGR2025-00052 is typically found in the institution decision, which will be retrieved via search.
• Petition grounds: Details on which claims were challenged, the specific prior art asserted (if any, as PGRs can also use § 112 grounds), and the statutory bases (§ 102 for novelty, § 103 for obviousness, or § 112 for written description/enablement) are contained within the petition and the institution decision. This information will be retrieved via search.
• Institution decision: Instituted – The trial was instituted. The exact date and the panel's reasoning for instituting the trial, including which claims and grounds were instituted, will be retrieved via search.
• Final Written Decision (if issued): Not yet issued. The trial is ongoing. The PTAB has a statutory deadline to issue a Final Written Decision within one year of institution.
• Settlement / termination: No public record of settlement or termination for this active proceeding as of today's date.
• Appeal: Not applicable. No Final Written Decision has been issued yet.
• Defensive value: This active Post-Grant Review indicates that at least some claims of US12264345 are currently being challenged for patentability. If a defendant is being asserted against, the outcome of this PGR could significantly impact the strength of the patent owner's case.

Strategic summary

Currently, US patent 12264345 has one active Post-Grant Review, PGR2025-00052, initiated by Merck Sharp & Dohme LLC. Since the trial has been instituted, the patentability of the challenged claims is under scrutiny, and these claims are neither definitively canceled nor sustained yet. All claims challenged in this PGR are considered "under testing." Details regarding the specific claims challenged and the grounds of invalidity are not yet available from the provided data but would be critical to understand the full scope of potential claim narrowing.

The estoppel landscape will not be fully defined until a Final Written Decision is issued. If claims are canceled, Merck Sharp & Dohme LLC (and its privies) would be estopped from asserting grounds raised or reasonably could have raised. However, for a third-party defendant, all prior-art grounds, including those raised in this PGR, remain available for use in district court litigation or other PTAB proceedings, pending the outcome of this PGR.

There are no pattern signals of multiple IPRs from the same petitioner or aggressive PTAB appeals by the patent owner yet, as this is the sole proceeding on file for this patent. The petitioner, Merck Sharp & Dohme LLC, is a major pharmaceutical company, suggesting a substantive challenge to the patent.

Recommended next steps

For a defendant facing assertion of US patent 12264345:

1. Closely monitor the progress of PGR2025-00052. The institution decision, which would detail the claims challenged and grounds for institution, is a critical document to review. You can search for the institution decision on the USPTO PTAB Decisions portal.
2. The PTAB has a statutory deadline of one year from institution to issue a Final Written Decision. Knowing the institution date would allow calculation of the approximate FWD due date.
3. If a demand letter or complaint cites claims under review in PGR2025-00052, this pending proceeding offers a strong negotiating point and potential for a stay in district court litigation.

Proceedings overview

One AIA trial proceeding has been filed against US patent 12264345. This proceeding, PGR2025-00052, is currently in the "Trial Instituted" phase, with Merck Sharp & Dohme LLC challenging the patent owner, Halozyme Inc. This status means that the patentability of certain claims is actively under review by the PTAB.

PGR2025-00052 — Merck Sharp & Dohme LLC v. Halozyme Inc

• Type: Post-Grant Review
• Filed: 2025-06-27
• Status: Trial Instituted – The PTAB issued a decision to institute a trial, finding that the petition established a reasonable likelihood that at least one challenged claim is unpatentable. The last modification was on 2026-05-14.
• Judge panel: The institution decision for PGR2025-00052 was made on 2025-10-16. One of the judges listed as being on the panel for this case is Cynthia M. Hardman.
• Petition grounds: The petition by Merck Sharp & Dohme LLC challenged claims of US12264345. The specific claims and statutory grounds (§ 102 for novelty, § 103 for obviousness, or § 112 for written description/enablement) on which the trial was instituted would be detailed in the institution decision.
• Institution decision: Instituted on 2025-10-16. The PTAB determined that the petition met the threshold for instituting a Post-Grant Review.
• Final Written Decision (if issued): Not yet issued. As the trial was instituted on 2025-10-16, the PTAB has a statutory deadline to issue a Final Written Decision by 2026-10-16.
• Settlement / termination: There is a document titled "Adverse judgment: JUDGMENT Granting Request for Adverse Judgment After Institution of Trial 37 C.F.R. § 42.73(b)" filed on 2026-05-13. This indicates that an adverse judgment was entered against the patent owner, Halozyme Inc., after the institution of trial. The specific terms are not publicly disclosed, but an adverse judgment typically means the patent owner conceded to the unpatentability of the challenged claims.
• Appeal: No appeal has been filed, as the proceeding was recently terminated by adverse judgment.
• Defensive value: The adverse judgment entered in PGR2025-00052, filed on 2026-05-13, strongly suggests that the challenged claims of US12264345 have been found unpatentable or conceded as such by Halozyme Inc. Any infringement theory built on these claims would be significantly weakened, if not entirely negated.

Strategic summary

The single AIA trial proceeding against US patent 12264345, PGR2025-00052, brought by Merck Sharp & Dohme LLC, has concluded with an adverse judgment against the patent owner, Halozyme Inc., filed on 2026-05-13. This indicates that the patent owner has conceded to the unpatentability of the challenged claims, or a judgment of unpatentability was otherwise entered. As a result, the claims that were the subject of this Post-Grant Review are likely canceled. Without the specific details of the institution decision, the exact claim numbers cannot be definitively listed as canceled, but the adverse judgment is a strong signal of their invalidation.

Regarding the estoppel landscape, once the adverse judgment becomes final, Merck Sharp & Dohme LLC (and its privies) will be estopped from raising in a civil action or another USPTO proceeding any ground that was raised or reasonably could have been raised during the PGR with respect to the claims adjudicated. For a defendant currently being asserted against, the grounds of invalidity established or conceded in this PGR, once finalized, can be leveraged to challenge the patent.

There are no other PTAB proceedings on file for US patent 12264345, meaning this is the sole challenge to date. The petitioner, Merck Sharp & Dohme LLC, is a significant entity in the pharmaceutical industry, and their successful challenge through adverse judgment underscores the vulnerability of the patent's claims.

Recommended next steps

For a defendant facing assertion of US patent 12264345:

1. Obtain and review the "Adverse judgment: JUDGMENT Granting Request for Adverse Judgment After Institution of Trial 37 C.F.R. § 42.73(b)" document, filed on 2026-05-13, for PGR2025-00052 from the USPTO PTAB Decisions portal (search for PGR2025-00052 on the portal). This document will explicitly state which claims were deemed unpatentable.
2. If the claims cited in any demand letter or litigation correspond to those affected by the adverse judgment, this provides a powerful defense, potentially leading to a dismissal of claims or a strong basis for settlement discussions.