Jonas Hannestad, MD, PhD: Phase 1b Interim Data on GT-02287 in Parkinson Disease

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"In addition to [the positive safety data], we are looking at various mechanistic biomarkers which will tell us whether this drug works the same way in humans and people with Parkinson disease as what we've seen in rodent models."

GT-2287, an investigational small-molecule therapy for Parkinson disease (PD), is showing promising early safety and tolerability results in an ongoing phase 1b open-label trial. The candidate, developed by Gain Therapeutics, is an orally bioavailable dopamine-modulating agent designed to target disease-related biology observed in preclinical models.

Interim data from the ongoing 90-day study, were presented at the 2025 International Congress of Parkinson’s Disease and Movement Disorders (MDS), held October 5-9, in Honolulu, Hawaii. The study is being conducted in Australia, and has completed enrollment with 21 participants with PD. The primary objective is to assess safety and tolerability, while secondary aims include evaluation of mechanistic biomarkers to confirm central nervous system target engagement.

While on-site at the congress, NeurologyLive sat down with Jonas Hannestad, MD, PhD, the chief medical officer at Gain, to glean some of his insight into what these data reveal about the therapy's potential. He discussed the safety data, which have shown posiitve signals to date in the current PD population and the preceding phase 1 trial in healthy volunteers.

Hannestad noted that of all recorded adverse events across the Parkinson disease cohort, 85% have been classified as mild, 10% as moderate, and fewer than 5% as severe. Only 3 participants required dose reductions for tolerability-related reasons, and a single participant discontinued the study due to adverse effects, suggesting overall favorable tolerability.

Additionally, he explained that CSF samples are being collected from each participant at baseline and again following 90 days of treatment, with the goal of assessing pharmacodynamic changes in central biomarkers. While those analyses are still pending, the biomarker data are expected by the end of the year. These findings will help inform further development and potential advancement into larger trials focused on disease modification.

Click here to read more from MDS 2025.

REFERENCES
1. Pozzi R, Ignoni T, Bosetti M, et al. GT-02287 in Parkinson’s Disease: Interim Data from a Phase 1b Study. Presented at: International Congress of Parkinson’s Disease and Movement Disorders; October 5-9, 2025; Honolulu, HI.