Inhaled Mebufotenin (GH001) for Adult Patients With Postpartum Depression: A Phase 2a Open-Label Clinical Trial

Objective: Postpartum depression (PPD) is a debilitating mood disorder with peripartum onset. Current treatment options are limited in PPD. GH001 is a synthetic inhalation formulation of the psychoactive molecule mebufotenin (5-MeO-DMT). This trial investigated the preliminary efficacy and safety of GH001 in adult females with PPD.

Methods: This phase 2a, proof-of-concept, open-label trial enrolled women aged 18-45 years (March 2023 to August 2024) with a Mini-International Neuropsychiatric Interview-confirmed diagnosis of major depressive disorder with peripartum onset. Patients had Montgomery-Asberg Depression Rating Scale (MADRS) scores of ≥28 at baseline. GH001 was administered as an individualized dosing regimen of up to 3 escalating doses (6, 12, and 18 mg) on day 1. The primary end point was the change in MADRS total score from baseline to day 8. Secondary end points included antidepressant response (≥50% reduction), remission (MADRS total score ≤10), and safety and tolerability of GH001.

Results: Ten patients were enrolled. Mean baseline MADRS total score was 36.7 (SD = 4.8). Mean MADRS total score change from baseline to day 8 was -35.4 points (SD = 5.5; P < .0001). All patients achieved response and were in remission on day 8, which was first observed 2 hours after their final dose on day 1. Inhalation of GH001 was well tolerated, and no serious adverse events (AEs) were reported. All treatment-emergent AEs were mild or moderate, with headache as the most frequently reported AE.

Conclusion: GH001 demonstrated rapid and significant improvements in depressive symptoms and remission of PPD with an acceptable safety profile and parallel improvements across secondary end points.

Trial Registration: ClinicalTrials.gov identifier: NCT05804708; EudraCT identifier: 2021-006879-42.