GT-02287 Phase 1b (GCase modulator)

The research record

This is the project's file for this landmark, as written and checked. Sources are listed at the end; anything not yet confirmed is marked "Not yet verified".

Who

Gain Therapeutics, sponsor. The study runs at seven sites in Australia, according to the company. Interim results were presented by the company's chief medical officer at the 3rd International GBA1 Meeting (Phoenix, 22–23 May 2026) and released on 26 May 2026.

What happened

GCase is the enzyme made by the GBA1 gene. Faulty GCase raises the risk of Parkinson's (landmark 16), and low GCase and synuclein feed each other (landmark 35). GT-02287 is a brain-penetrant tablet that binds GCase at a site away from its working part (an "allosteric" modulator) and is meant to restore its function. The study enrolled people with or without a GBA1 mutation; the release reports results by baseline marker level, not by GBA1 status.

• Design. ClinicalTrials.gov NCT06732180: open-label (no placebo), single group, planned 20 people, started 21 Feb 2025 (the record was last updated in May 2025, still "recruiting"). Adults aged 30 to 85, within 7 years of diagnosis, Hoehn and Yahr stage 1 to 3. Treatment is once a day for 90 days, then an extension up to 12 months in total. Main measure: safety and tolerability.
• Reported to May 2026 (company statements). 19 people finished the first 90 days, and 16 of them went on to the extension (all still on study at day 150). Spinal-fluid glucosylsphingosine, a GCase substrate marker, fell on average 81% after 90 days in those who started with high levels. The MDS-UPDRS Parts II + III score was described as "stable and durable" at day 150, with a 4.8-point greater benefit in the high than the low starting-marker group; the company says that difference was not a formal endpoint. On safety, a data monitoring committee met on 5 March 2026 and said the study should continue unchanged; no adverse-event numbers were in the release.
• Next. A Phase 2 (NCT07280299), 111 people with early Parkinson's, randomised, main measure the MDS-UPDRS Part II + III sum at week 48, is listed as not yet recruiting (record last updated 12 Dec 2025; estimated start 30 May 2026, primary completion June 2028). A company release of 29 June 2026 says the US FDA cleared its application and a US start is expected in the third quarter of 2026. I found no report that anyone has been dosed.

Why it moved us toward a cure

It is a second kind of GCase drug, after the failed activator BIA 28-6156 (landmark 235) and in addition to ambroxol (landmark 40). Its candidate marker, glucosylsphingosine, may help pick who responds. With no control group and about 20 people, it cannot show slowing of the disease.

Outcome

Open. Safety and marker data are early, company-reported and unreviewed. Whether the drug helps will depend on the Phase 2.

Sources

• Gain Therapeutics release, 26 May 2026 (BioSpace)
• ClinicalTrials.gov NCT06732180 · NCT07280299 (read from the registry API)
• Gain Therapeutics IND clearance, 29 Jun 2026 (via Panabee)
• Not yet verified: the exact doses; safety numbers; whether the registry's planned 20 matches the actual enrolment; how many participants had GBA1 variants; the Phase 1 healthy-volunteer results; whether the Phase 2 has started; any independent or peer-reviewed analysis.