Unknown Petitioner v. Enveric Biosciences Canada Inc.

This Post-Grant Review (PGR) proceeding at the Patent Trial and Appeal Board (PTAB), case number PGR2025-00076, involved Enveric Biosciences Canada Inc. as the patent owner and Gilgamesh Pharmaceuticals, Inc. as the petitioner. Enveric Biosciences is a biotechnology company focused on developing novel neuroplastogen small-molecule therapeutics for neuropsychiatric disorders, including depression, anxiety, and addiction, leveraging its "Psybrary™" discovery platform. Gilgamesh Pharmaceuticals, Inc. initiated the PGR, which Enveric Biosciences stated was relevant to the bretisilocin molecule (GM-2505), a compound reportedly acquired by AbbVie, Inc..

The PGR challenged the validity of U.S. Patent No. 12,138,276, owned by Enveric Biosciences Canada Inc. While the full technical details of the patent are not immediately available, Enveric Biosciences' public statements indicate the patent is relevant to the bretisilocin molecule (GM-2505), suggesting it covers chemical compounds or methods related to neuroplastogen therapeutics for treating neuropsychiatric conditions. In a PGR, there is no "accused product" in the traditional sense of an infringement suit; rather, the petitioner seeks to invalidate the patent claims.

The procedural posture of the case is a Post-Grant Review before the Patent Trial and Appeal Board (PTAB) of the United States Patent and Trademark Office (USPTO). The case reached a "Procedural Termination" because Gilgamesh Pharmaceuticals, Inc. withdrew its petition. The PTAB provides an administrative forum for challenging patent validity, with PGRs allowing for broader invalidity grounds than inter partes reviews (IPRs) for recently issued patents. The withdrawal by Gilgamesh Pharmaceuticals means the PTAB did not issue a substantive decision on the patentability of claims in US Patent No. 12,138,276, leaving the patent intact from this particular challenge.

This case is notable due to the highly competitive and evolving field of neuropsychiatric therapeutics, particularly concerning psychedelic-inspired compounds. The involvement of biotechnology firms like Enveric Biosciences, which focuses on developing neuroplastogen small molecules without hallucinogenic effects, highlights a significant area of pharmaceutical innovation. The link to bretisilocin (GM-2505) and its acquisition by AbbVie, Inc., underscores the potential commercial value of the intellectual property at stake. The termination of the PGR by withdrawal, rather than a final decision on the merits, often signals a confidential settlement or a strategic decision by the petitioner to pursue alternative avenues.

Key Legal Developments and Outcome for PGR2025-00076

This summary details the Post-Grant Review (PGR) proceeding, PGR2025-00076, before the Patent Trial and Appeal Board (PTAB) involving U.S. Patent No. 12,138,276. There is no indication of a parallel district court patent infringement litigation related to this patent.

Parallel PTAB IPR/PGR Proceedings & Their Effect:

• 2025-08-12: PGR Petition Filed. Gilgamesh Pharmaceuticals filed a Post-Grant Review petition (PGR2025-00076) against Enveric Biosciences' U.S. Patent No. 12,138,276, titled "Halogenated psilocybin derivatives and methods of using". The petition specifically targeted claims that appeared relevant to Gilgamesh's Bretisilocin (GM-2505) molecule, which was in clinical trials.
• 2025-08-25: AbbVie Acquires Bretisilocin. AbbVie Inc. agreed to acquire Bretisilocin from Gilgamesh Pharmaceuticals in a transaction valued at up to $1.2 billion.
• 2025-10-15: Enveric Retains Counsel. Enveric Biosciences announced it had hired Fish & Richardson P.C. to contest Gilgamesh's PGR petition.
• 2025-10-17: Gilgamesh Becomes AbbVie Subsidiary. Gilgamesh Pharmaceuticals, Inc. became a wholly owned subsidiary of Warka Intermediate LLC, which is a wholly owned subsidiary of AbbVie Inc..
• 2025-10-24: Enveric Files Request for Discretionary Denial. Fish & Richardson filed a Request for Discretionary Denial of the PGR petition on behalf of Enveric.
• 2025-11-07: Gilgamesh Identifies Real Parties-in-Interest. Gilgamesh notified the PTAB that Warka Intermediate LLC and AbbVie Inc. were the real parties-in-interest in the proceeding.
• 2025-11-20: AbbVie Requests Withdrawal of Petition. Counsel for AbbVie filed a request with the USPTO to withdraw the PGR petition that Gilgamesh had filed.
• 2026-02-25: Procedural Termination (Withdrawal of Petition). Enveric Biosciences announced that the PGR petition filed by Gilgamesh Pharmaceuticals (and subsequently inherited by AbbVie Inc.) against U.S. Patent No. 12,138,276 had been withdrawn. This action followed Enveric's filing of a request for discretionary denial of the petition. As a result, there were no remaining challenges pending against Enveric's patent.

Outcome:

The PGR proceeding, PGR2025-00076, concluded with a procedural termination due to the petitioner's withdrawal of the petition on February 25, 2026. This withdrawal occurred after Enveric Biosciences filed a request for discretionary denial and after AbbVie Inc. acquired Gilgamesh Pharmaceuticals, becoming the real party-in-interest.

The petitioner in PGR2025-00076 is currently unknown. Due to the lack of information regarding the petitioner's identity, it is not possible to identify the counsel of record representing them in this Post-Grant Review proceeding.

Enveric Biosciences Canada Inc., the patent owner in PGR2025-00076, was represented by intellectual property law firm Fish & Richardson P.C..

Counsel of Record for Enveric Biosciences Canada Inc.:

• Firm: Fish & Richardson P.C.
  • Enveric Biosciences announced in October 2025 that it had hired Fish & Richardson P.C. to contest the PGR petition. The firm subsequently filed a Request for Discretionary Denial of the PGR petition on behalf of Enveric.

Specific attorneys from Fish & Richardson P.C. were not identified in the provided search results for this particular case (PGR2025-00076). While some PTAB documents indicate general counsel representation for different patent owners, they do not specifically name the individual attorneys representing Enveric Biosciences in PGR2025-00076.