GH Research PLC (NASDAQ:GHRS) and Definium Therapeutics Inc. (NASDAQ:DFTX) stocks are trading higher in response to Eli Lilly and Co. (NYSE:LLY) agreeing to acquire AtaiBeckley Inc. (NASDAQ:ATAI) in a deal valued at up to $3.80 billion.

Bloomberg was the first to report the deal. AtaiBeckley is one of several companies poised to usher in this new era of psychedelics.

GH001 Draws Comparisons With AtaiBeckley’s Lead Drug Candidate

GH Research’s lead drug, GH001, is formulated for mebufotenin administration via a proprietary inhalation approach, similar to AtaiBeckley’s lead asset, BPL-003 (mebufotenin benzoate), administered intranasally for treatment-resistant depression.

Prior Data Supports Treatment-Resistant Depression Program

In March 2026, the results of the Phase 2b trial in TRD (GH001-TRD-201) were published in JAMA Psychiatry.

A post-hoc analysis reported alongside the publication demonstrated efficacy independent of the number of prior antidepressant treatment failures, with Day 8 remission rates of 53.9%-63.6% across subgroups.

In May, GH Research said it completed enrolment in a Phase 1 pharmacology trial in the U.K., evaluating a proprietary aerosol delivery device for the administration of GH001 in healthy volunteers (GH001-HV-106).

The company selected the doses for the global Phase 3 pivotal program based on the results from this trial for treatment-resistant depression.

In January, the U.S. Food and Drug Administration (FDA) lifted the clinical hold on GH Research’s Investigational New Drug Application (IND) for GH001 after the FDA placed a clinical hold in September 2023 due to insufficient information to assess risks to human subjects.

Shorter Treatment Duration For BPL-003

Bloomberg’s report on Thursday noted that BPL-003’s shorter treatment duration is a key advantage.

Its psychedelic effects last about one to two hours, compared with some experimental therapies, including one from Compass Pathways Plc (NASDAQ:CMPS), that may require patient monitoring for up to eight hours.

Price Action: GH Research shares were up 11.40% at $29.99, and Definium Therapeutics shares were down 1.31% at $45.06 at the time of publication on Thursday, according to Benzinga Pro data.

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