Gh Research Plc SEC Filings

GH Research PLC reported new clinical data on its investigational inhaled psychedelic GH001 (synthetic mebufotenin) across several depressive disorders, presented at an ACNP 2026 mini‑panel. In a Phase 2b double‑blind trial in treatment‑resistant depression, GH001 achieved the primary endpoint with a least‑squares mean MADRS reduction on Day 8 that was 15.5 points greater than placebo, with a Cohen’s d effect size of −2.0. At Day 8, 60.0% of GH001 patients met response criteria and 57.5% achieved remission, versus 0% on placebo, and among open‑label extension completers 73% were in remission at 6 months. A Phase 2a postpartum depression trial (10 patients) showed all patients in remission by Day 8 and a mean 35.4‑point MADRS reduction, alongside a 34.1‑point improvement in maternal functioning scores and rapid elimination of mebufotenin and its metabolites from breastmilk. Across TRD, PPD and bipolar II depression with a current major depressive episode, GH001 produced rapid, clinically meaningful improvements in MADRS anhedonia subscale scores and was generally well tolerated, with mostly mild to moderate treatment‑emergent adverse events and no treatment‑related serious events or suicidal behavior reported.

GH Research PLC reported detailed Phase 2b data for GH001, an inhaled synthetic 5‑MeO‑DMT, in adults with treatment‑resistant depression. In the double‑blind part, GH001 led to a least squares mean reduction in MADRS depression score that was −15.5 points greater than placebo at Day 8, with an effect size (Cohen’s d) of −2.0, and a remission rate (MADRS ≤10) of 57.5% after a single dose. Among open‑label extension completers, remission reached 73.0% at Month 6 after a mean of four treatments.

GH001 also reduced global illness severity: CGI‑S scores improved by an LS mean of −2.4 versus 0.1 for placebo at Day 8, with a −2.5 LS mean difference, and a −3.0 mean CGI‑S change by Month 6 in extension completers. Anxiety symptoms improved, with an LS mean HAM‑A change of −11.1 for GH001 versus −1.0 for placebo at Day 8 and a −10.0 LS mean difference, and a −13.3 mean HAM‑A change at Month 6. Quality of life (Q‑LES‑Q‑SF) increased, with a 20.6‑point LS mean improvement versus −0.8 for placebo at Day 8 and a 24.8‑point mean gain at Month 6. GH001 was generally well tolerated over up to six months, with mostly mild or moderate treatment‑emergent adverse events and no reported flashbacks, suicidal intent, or suicidal behavior.

GH Research plc reports new clinical data on its inhaled psychedelic candidate GH001 in treatment-resistant depression. In a randomized Phase 2b trial with a 6‑month open-label extension, 81 patients were treated with either GH001 or placebo and then all received GH001 in the extension. Suicidal ideation and behavior were assessed repeatedly using the Columbia-Suicide Severity Rating Scale and MADRS item 10.

No treatment-emergent adverse events of suicidal intent or suicidal behavior occurred over 6 months. One patient had a treatment-emergent adverse event of suicidal ideation lasting 6 hours and resolving spontaneously. Baseline suicidality and changes through Day 8 were generally similar between GH001 and placebo, and the proportion of patients with zero suicidality scores increased over time during the extension. The company concludes that GH001 was generally well tolerated and associated with significant reductions in depressive symptoms without increasing suicide risk in this TRD population.

GH Research PLC reports that it has been accepted to the Promising Targets Oral Session at the 64th American College of Neuropsychopharmacology annual meeting. The company will present results from its GH001-TRD-201 clinical trial, which focuses on treatment‑resistant depression, during this scientific congress. The meeting is scheduled for January 12–15, 2026 in Nassau, Bahamas, and the presentation will be delivered by Prof Michael E. Thase. An abstract of the presentation content is provided as an exhibit to this report, giving additional detail on the trial results to the scientific and investment community.

GH Research PLC (GHRS) reported that it will participate in a fireside chat and hold one-on-one investor meetings during the Stifel 2025 Healthcare Conference in New York. The conference is scheduled for November 11–13, 2025.

This is a routine investor-relations update that signals engagement with the investment community through a formal conference appearance and direct meetings.

GH Research PLC furnished a Form 6-K announcing third quarter 2025 financial results, business updates, and an updated investor presentation. The company made available a press release and presentation dated November 6, 2025.

The submission includes unaudited interim financial statements and MD&A, plus Inline XBRL files. The report (excluding Exhibits 99.3 and 99.4) is incorporated by reference into the company’s Form S-8 registrations and its Form F-3 shelf.

GH Research PLC reported that posters from its GH001-TRD-201 clinical program were accepted for presentation at the 64th American College of Neuropsychopharmacology annual meeting, scheduled for January 12–15, 2026 in Nassau, Bahamas. The submission set includes three abstracts: suicidal ideation and behavior in treatment-resistant depression (Ex. 99.1; presenter Sanjay J. Mathew), rapid antidepressant effects of inhaled GH001 in treatment-resistant depression from a Phase 2b randomized trial with 6‑month follow-up (Ex. 99.2; presenter Lisa Harding), and efficacy and safety of inhaled mebufotenin (GH001) in Bipolar II depression from a Phase 2a trial (Ex. 99.3; presenter Andreas Reif).

GH Research PLC filed a Form 6-K announcing the presentation of data from its GH001-TRD-201 clinical trial at the 38th European College of Neuropsychopharmacology annual meeting in Amsterdam. The Congress is scheduled for October 11–14, 2025.

The presentation, delivered by Prof. Wiesław J. Cubała on October 13, 2025 during the Novel Therapies Symposium, is provided as Exhibit 99.1. This update is informational and centers on the public disclosure of clinical data via a scientific conference presentation.

GH Research PLC reports that it will present clinical data from its GH001-TRD-201 trial in treatment-resistant depression at the 38th European College of Neuropsychopharmacology (ECNP) annual meeting in Amsterdam from October 11-14, 2025.

One poster, presented by Dr. Fabian Devlin on October 13, 2025, will cover the psychoactive effects of GH001 in patients with treatment-resistant depression from a Phase 2b, double-blind, randomised controlled trial. A second poster, presented by Prof. Bernhard T. Baune on October 14, 2025, will address safety and tolerability results from the same Phase 2b, double-blind trial with an open-label extension of GH001 in treatment-resistant depression.