Gh Research Plc SEC Filings

GH Research PLC, an Ireland-based clinical-stage biopharmaceutical company, files its annual report outlining 2025 results and key risks. The company is developing mebufotenin-based therapies GH001 and GH002 for treatment-resistant depression and other psychiatric and neurological disorders and has no approved products or product revenue.

GH Research reported a 2025 net loss of $48.3 million, up from $39.0 million in 2024, and had an accumulated deficit of $154.4 million as of December 31, 2025, with 62,029,395 ordinary shares outstanding. Management expects significant continuing losses and substantial additional funding needs to complete clinical development, build devices required to deliver its drugs, and potentially commercialize any approved products.

The report highlights extensive risk factors, including reliance on a small set of early-stage clinical trials, potential side effects, complex drug–device combination requirements, foreign exchange exposure, and regulatory uncertainty. The FDA placed a clinical hold on the GH001 IND in 2023 to require additional inhalation toxicology studies, and lifted the hold in December 2025 after the requested work was completed, allowing U.S. clinical development to proceed, though future holds or delays remain possible.

GH Research PLC reported a larger 2025 net loss while advancing its lead depression therapy GH001 through a successful Phase 2b trial. The trial in treatment-resistant depression met its primary endpoint, with a placebo-adjusted MADRS reduction of 15.5 points at Day 8 and 57.5% remission versus 0% on placebo in the double-blind phase.

In the six-month extension, 73% of completers were in remission with relatively few retreatment visits, and 99% of dosing visits saw patients discharge-ready within an hour, with no treatment-related serious adverse events. Cash, cash equivalents and marketable securities rose to $280.7 million as of December 31, 2025, while the company recorded a net loss of $48.3 million, or $0.79 per share, driven by higher research and development and general and administrative expenses.

GH Research PLC received an updated ownership disclosure showing that investment manager Lynx1 Capital Management LP and Weston Nichols together beneficially own 10,406,575 ordinary shares. This represents 16.8% of GH Research’s ordinary shares, based on 62,029,395 shares outstanding as of September 30, 2025.

The shares are held through the Lynx1 Master Fund LP and a managed account, with Lynx1 and Nichols sharing voting and dispositive power over the stake. They certify that the position was not acquired to change or influence control of GH Research, indicating a passive investment intent under Schedule 13G rules.

GH Research PLC, an Ireland-based biopharmaceutical company, reported that it will take part in a panel discussion at the RBC Capital Markets Psychedelics Symposium: A Trip Into The Future of Mental Health. The event is scheduled to be held virtually on January 22, 2026.

The company will be represented in this regulatory report by Julie Ryan, Vice President, Finance, who signed the submission on behalf of GH Research PLC. The filing is primarily informational and highlights the company’s participation in an industry-focused conference rather than providing financial or operating results.

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.