After spending two years in regulatory purgatory, GH Research Plc (GHRS) finally got the green light it's been waiting for. The FDA lifted its clinical hold on Monday for the company's Investigational New Drug Application for GH001, an inhalable treatment for depression that showed promising results before regulators pumped the brakes.
The timing matters here. GH Research originally hit a regulatory wall in September 2023 when the FDA placed the clinical hold, citing insufficient information to properly assess risks to human subjects. That's FDA-speak for "we need more data before you can keep testing this on people." Now, with that hold lifted, the company can actually do something with the impressive Phase 2b results it released back in February.
"The FDA clearance is a major milestone and positions us to advance GH001 as a potential ultra-rapid and durable treatment option for TRD patients," said Dr. Velichka Valcheva, Chief Executive Officer. "We continue to expect initiation of our global pivotal program in 2026. We look forward to meeting with the FDA to align on the design for the pivotal Phase 3 program."
The Trial Results That Got Everyone's Attention
So what made this drug worth the two-year wait? The Phase 2b trial tested GH001, an inhalable bufotenin product, in patients with treatment-resistant depression. The results were statistically significant and clinically meaningful. Patients taking GH001 saw their Montgomery-Åsberg Depression Rating Scale scores drop by 15.2 points from baseline by Day 8. The placebo group? They improved by just 0.3 points. That's a treatment difference of 15.5 points with a p-value less than 0.0001, which in statistics language means this wasn't a fluke.
Michael E. Thase, MD, Professor of Psychiatry at the Perelman School of Medicine at the University of Pennsylvania, framed the implications clearly: "The large and rapid antidepressant effect observed with GH001 in the Phase 2b trial, combined with sustained remission through infrequent, short clinic visits, has the potential to be practice-changing for patients with treatment-resistant depression."
A Crowded Field Getting More Competitive
GH Research isn't operating in a vacuum. The treatment-resistant depression space has seen significant activity recently. In January, the FDA approved Johnson & Johnson (JNJ) supplemental New Drug Application for Spravato (esketamine) nasal spray as the first and only monotherapy for adults with major depressive disorder who haven't responded to at least two oral antidepressants.
Then in June, Alto Neuroscience Inc. made a big bet by purchasing Chase Therapeutics Corporation's portfolio of dopamine agonist drug combinations for treatment-resistant depression, paying over $100 million for the assets. And in September, Atai Life Sciences (ATAI) and Beckley Psytech released proof-of-concept data from their own study investigating BPL-003, an intranasal treatment for treatment-resistant depression using a two-dose induction regimen.
The market clearly sees potential here. GH Research shares jumped 34.52% to $17.86 on Monday following the FDA announcement, according to market data.




