GH Research Announces Two-Peer Reviewed Publications From Its Phase 2B Clinical Program Of GH001 For Treatment-Resistant Depression

GH Research PLC (NASDAQ:GHRS), a clinical-stage biopharmaceutical company dedicated to transforming the lives of patients by developing a practice-changing treatment in depression, today announced two peer-reviewed publications from its Phase 2b clinical program of GH001 in treatment-resistant depression (TRD): the primary trial results in JAMA Psychiatry, and a new analysis demonstrating that efficacy is independent of the number of prior lifetime treatment failures in a forthcoming issue of Psychopharmacology Bulletin.

The peer-reviewed article, titled "GH001 vs Placebo in Patients with Treatment-Resistant Depression" has been published today in JAMA Psychiatry (DOI: 10.1001/jamapsychiatry.2026.0096). The publication includes the complete results from the randomized, double-blind, placebo-controlled Phase 2b trial of mebufotenin in patients with TRD, including all primary and secondary efficacy endpoints, safety and tolerability data, and initial results from the 6-month open-label extension. These results were previously reported in topline form.

In TRD, a well-established finding across multiple treatment modalities is that remission rates decline significantly with each successive antidepressant treatment failure. This pattern, first quantified in the landmark STAR*D trial (see About STAR*D below), represents a fundamental challenge in treating patients with extensive treatment histories. The new analysis of Phase 2b data demonstrates that GH001 does not follow this pattern:

• Day 8 remission rates ranged from 53.9% to 63.6% across patients with 2 to ≥5 prior lifetime antidepressant failures, with no decline at higher failure counts;
• End of trial/Month 6 remission rates ranged from 61.5% to 85.7% across the same subgroups; and
• No meaningful correlation was observed between the number of prior lifetime treatment failures and Montgomery-Åsberg Depression Rating Scale (MADRS) improvement at Day 8 (r=−0.13; P=0.44) or among those who completed the 6-month OLE (r=−0.10; P=0.60).