PTAB challenges

Proceedings overview

A single AIA trial proceeding, PGR2026-00013, has been filed against US Patent 12233106. The petition for Post-Grant Review was denied institution, meaning no claims were challenged on the merits at trial. This outcome gives the patent owner, Biomarin Pharmaceutical Inc., a strengthened defensive posture, as the patent has successfully withstood an initial validity challenge at the PTAB.

PGR2026-00013 — Ascendis Pharma A/S et al. v. Biomarin Pharmaceutical Inc.

• Type: Post-Grant Review (PGR)
• Filed: 2025-11-24
• Status: Institution Denied (overriding the "Trial Instituted" status provided in the prompt's structured data, based on the authoritative USPTO decision document). The Patent Trial and Appeal Board (PTAB) declined to institute a trial.
• Judge panel: John A. Squires, Under Secretary of Commerce for Intellectual Property and Director of the United States Patent and Trademark Office.
• Petition grounds: The specific claims and prior art grounds raised in the petition are not detailed in the public institution denial notice. However, the decision indicates the petitioner failed to meet the statutory threshold for institution.
• Institution decision: Denied on 2026-03-23. The Director determined that "the petitioner has failed to show a reasonable likelihood of prevailing with respect to at least one of the claims challenged in the petition or that it is more likely than not that at least one of the claims challenged in the petition is unpatentable, as appropriate. Accordingly, institution of inter partes review or post-grant review is denied".
• Final Written Decision: Not applicable, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: Not applicable for a denial of institution on the merits at the Director level in the same manner as a Final Written Decision.
• Defensive value: This proceeding demonstrates that the PTAB found Ascendis Pharma A/S's arguments for unpatentability insufficient to warrant a full review. Consequently, all claims of US12233106 remain patentable as far as this PGR is concerned, and the patent owner's position is strengthened.

Strategic summary

All nine independent claims (Claims 1, 9, 17, 25, 33, 42, 43, 44, and 45) and their associated dependent claims of US12233106 remain UNTESTED by a PTAB Final Written Decision. The sole PGR petition, PGR2026-00013, filed by Ascendis Pharma A/S, was denied institution, meaning the PTAB did not proceed to a full trial on the merits of the challenged claims.

Regarding estoppel, under 35 U.S.C. § 325(e)(1), the petitioner, Ascendis Pharma A/S, and its privies are likely estopped from asserting in any other U.S. patent or civil action, or before the International Trade Commission, that a claim is invalid on any ground that the petitioner raised or reasonably could have raised during the PGR. This means that if Ascendis Pharma A/S were to face an infringement suit on US12233106, they would be barred from using the same prior art or arguments for invalidity that they presented (or could have presented) in the denied PGR petition. Other potential defendants not in privity with Ascendis Pharma A/S are not subject to this estoppel and could still challenge the patent.

The sole PTAB activity shows a patent owner successfully defending against a PGR petition. The petitioner, Ascendis Pharma A/S, is noted as having ongoing litigation with BioMarin Pharmaceutical Inc. concerning C-type natriuretic peptide (CNP) variants for treating achondroplasia, as indicated by Federal Circuit appeal 2026-1026. This context suggests a competitive landscape in the pharmaceutical industry rather than a defensive aggregator like Unified Patents, although the initial Google Patents summary did mention "Unified Patents PTAB Data" as a petitioner for PGR2026-00013. However, the more specific "PTAB proceedings on file" block in the prompt explicitly lists Ascendis Pharma A/S as the petitioner, which is the canonical source for this analysis.

Recommended next steps

Given that PGR2026-00013 was denied institution, no claims of US12233106 were invalidated by the PTAB. For a defendant facing assertion of this patent, this means all claims are currently presumed valid from a PTAB perspective.

The institution decision for PGR2026-00013 can be reviewed for its specific reasoning. The official notice of denial, issued on March 23, 2026, by Director John A. Squires, states that the petitioner failed to show a reasonable likelihood of prevailing. This document is available through the USPTO's public records, and the reference provided is a direct link to it: https://vertexaisearch.cloud.google.com/grounding-api-redirect/AUZIYQFNNVET-TuzXs5O0hgdOcaelVmerOqM1ZJhhkcQRWV6TJBaF2p279nTCsg2lG57dvNbnmlZaXnfBCiATtY_HVs8t1ljF3t6zLsE2F6Zpr8VkekShxGe1hOksedxpJ7iavSqxajtmW4UE5y9sOKkRw6Lbz-F0eIvkN-yVhA7HIzgQzvIkOdzWh4WGFRmg27OgVct9us2R_mooRtFRVXSsl-klhPi-IHqvbEZrvRTMeB4TqCb7H42XDsI4y_fB3DM3fjQXz43rMXaHIxu4vjxfiTYqG8EirLuYQ==. There are no active PTAB proceedings to track for milestones. The absence of further PTAB activity on this relatively recently granted patent (issued 2025-02-25) after a denial of institution might signal that other potential challengers have assessed the patent as difficult to invalidate via AIA trials, or are pursuing other avenues.