Gilgamesh Withdraws Patent Fight Against Enveric After $1.2 Billion AbbVie Deal, CEO Says Key Drug Claims Now Uncontested

by | Feb 25, 2026 | General

Enveric Biosciences Inc. (NASDAQ:ENVB) on Wednesday said that the previously announced Post-Grant Review (PGR) petition filed by Gilgamesh Pharmaceuticals Inc. against Enveric’s issued U.S. Patent No. 12,138,276 (the ‘276 patent) has been withdrawn.

The action follows Enveric’s filing of a Request for Discretionary Denial of the petition. As a result, there are no remaining challenges currently pending against Enveric’s patent.

Enveric’s ‘276 patent, “Halogenated psilocybin derivatives and methods of using”, includes claims that appear relevant to the bretisilocin (GM-2505) molecule currently in clinical trials.

In August 2025, Gilgamesh filed a PGR petition in the United States Patent and Trademark Office, Patent Trial and Appeal Board (PTAB) against Enveric’s ‘276 patent.

Soon after, AbbVie Inc. (NYSE:ABBV) agreed to acquire bretisilocin from Gilgamesh in a definitive transaction valued at up to $1.2 billion.

In October 2025, Enveric hired Fish and Richardson P.C. to contest the PGR petition filed by Gilgamesh against Enveric’s ‘276 patent, and Fish and Richardson filed a Request for Discretionary Denial of the PGR petition on behalf of Enveric. 

In November 2025, counsel for AbbVie filed a request to the USPTO asking to withdraw the petition Gilgamesh had filed.

“Enveric is gratified by this turn of events, which we believe demonstrates our willingness to fully defend the intellectual property that protects our valuable discoveries,” said Joseph Tucker, Director and CEO of Enveric.

“The withdrawal of the petition resolves the proceeding and leaves our issued patent unchallenged. We believe it reflects both the strength of our intellectual property and our willingness to defend it when necessary,” Tucker told Benzinga.

Last week, Enveric Biosciences shared new mechanistic data demonstrating that its lead candidate, EB-003, activates both Gq- and β-arrestin–mediated signaling downstream of the 5-HT₂A receptor.

Price Action: ENVB stock is down 1.45% at $2.17 during the premarket session at the last check on Wednesday, according to Benzinga Pro data.

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