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GH Research plc (NASDAQ: GHRS) is a clinical-stage biopharmaceutical company founded in 2018 and headquartered in Dublin, Ireland, developing novel mebufotenin (5-MeO-DMT) therapeutics for treatment-resistant depression, bipolar II disorder, and postpartum depression. Its lead asset GH001 — an inhaled mebufotenin formulation — met the primary endpoint of its Phase 2b TRD trial in February 2025 with striking results: -15.5 point MADRS reduction vs placebo (p<0.0001) and 57.7% remission vs 0%. With a single-day dosing paradigm requiring no structured psychotherapy, GH001 is positioned as a differentiated asset; Phase 3 global initiation is planned for 2026 following FDA clinical hold lift. GH002 (IV mebufotenin) completed Phase 1 in healthy volunteers.

Development Programmes

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Phase III

Mebufotenin (5-MeO-DMT) delivered via a proprietary vaporization inhaler. Single or few inhalation sessions in a clinical setting. Phase 2b (NCT05800860) met primary endpoint: −15.2-point MADRS reduction vs +0.3 for placebo (p<0.0001); 57.7% remission. FDA clinical hold (Sep 2023) lifted Jan 5, 2026. Global Phase 3 program planned for 2026.

Programme Tracker

Treatment-Resistant Depression (TRD)

Primary: US (FDA)
Phase IIIActive

Forecast

Phase III started - Approval eventual: 50%

Phase 3 global pivotal program planned for 2026 initiation following FDA clinical hold lift (Jan 5, 2026) and positive Phase 2b results

Milestones

Phase II topline

Completed

Actual: Feb 3, 2025

Phase 2b (NCT05800860) primary endpoint met: GH001 reduced MADRS by 15.2 points vs +0.3 for placebo (p<0.0001); 57.7% remission at Day 8

Why it matters: Largest placebo-adjusted antidepressant effect seen in a controlled psychedelic trial; validated 5-MeO-DMT as a rapid-acting antidepressant in TRD

Watch next: FDA clinical hold resolution, Phase 3 programme initiation

Phase III started

Planned

Likely: Q3 2026

GH Research announced plans to initiate global pivotal Phase 3 programme in 2026

Why it matters: Pivotal trials needed to support NDA/MAA regulatory submissions for TRD

Watch next: Phase 3 ClinicalTrials.gov registration and first patient dosing announcement

Regulatory review accepted

Completed

Actual: Jan 5, 2026

FDA lifted clinical hold on GH001 IND (hold placed September 2023 for additional inhalation toxicology data)

Why it matters: Clears path for U.S. patient enrollment in Phase 3; non-rodent inhalation tox studies showed no respiratory toxicity

Watch next: Phase 3 programme initiation and first patient dosing

Recorded Events

Jan 5, 2026: Regulatory review accepted

Feb 3, 2025: Phase II topline

Evidence Links

NCT05800860 — GH001-TRD-201 Phase 2b Trial

trial-registry - ClinicalTrials.gov - Verified

GH001 Phase 1/2 TRD Publication (PMC)

Publication - PMC / Neuropsychopharmacology - Jul 1, 2023 - Verified

GH Research Pipeline Page

company-website - GH Research - Verified

Phase II

Inhaled GH001 for bipolar II disorder with a current major depressive episode. Phase 2a proof-of-concept (GH001-BD-202) met primary endpoint: MADRS reduction −16.8 points (51.9%) at Day 8 (p=0.0099; n=6). No further development announced.

Programme Tracker

Bipolar Disorder

Primary: US (FDA)
Phase IIpaused

Phase 2a completed Q4 2024; no further development in BDII announced. Recruitment challenges led to small n=6 treated sample.

Milestones

Phase II topline

Completed

Actual: Dec 1, 2024

Phase 2a (GH001-BD-202) met primary endpoint: MADRS −16.8 pts (51.9%) at Day 8 (p=0.0099); 33% patients in remission

Why it matters: Proof-of-concept signal in BDII; however, small n=6 and recruitment difficulties limit conclusions

Watch next: No further BDII development currently announced

Recorded Events

Dec 1, 2024: Phase II topline

Phase II

Inhaled GH001 for postpartum depression. Phase 2a proof-of-concept (GH001-PPD-203; n=10): all 10 patients in remission at Day 8 (mean MADRS 1.3). No further development announced.

Programme Tracker

Peripartum

Primary: US (FDA)
Phase IIpaused

Phase 2a completed Q4 2024. All 10 patients in remission — striking result. No further PPD development announced; resources focused on TRD Phase 3.

Milestones

Phase II topline

Completed

Actual: Dec 1, 2024

Phase 2a (GH001-PPD-203) met primary endpoint: all 10 patients in remission at Day 8 (mean MADRS 1.3)

Why it matters: 100% remission rate is an extraordinary clinical signal; PPD is an under-served indication with growing regulatory interest

Watch next: No further PPD programme currently announced; resources focused on TRD

Recorded Events

Dec 1, 2024: Phase II topline

Phase I

Intravenous formulation of mebufotenin (5-MeO-DMT) — distinct from GH001's inhaled route. Phase 1 healthy volunteer trial (GH002-HV-105; n=64) completed Q4 2023. Well tolerated, no serious adverse events. No patient indication announced.

Programme Tracker

Healthy Volunteers

Primary: US (FDA)
Phase ICompleted

Phase 1 HV study complete (Q4 2023). Safety, tolerability, and PK characterised for IV route. Next steps not yet announced.

Milestones

Phase I completed

Completed

Actual: Dec 31, 2023

GH002-HV-105 Phase 1 trial completed in 64 healthy volunteers; IV 5-MeO-DMT characterised for safety and PK at single and multiple doses

Why it matters: IV route may offer more precise dosing control than inhalation; validates GH002 for potential patient trials

Watch next: Patient indication selection and Phase 2 planning

Recorded Events

Dec 31, 2023: Phase I completed

Evidence Links

GH Research — Clinical Trials Overview

company-website - GH Research - Verified

Quick Facts

Type
Public Biotech
Founded
2018
Ticker
NASDAQ: GHRS
Lead Stage
Phase III
HQ
28 Baggot Street Lower, Dublin 2, Ireland, Ireland
Website
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Sponsored Trials

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Research Papers

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