Gain Therapeutics Reports Early Parkinson's Study Showing Brain Biomarker Improvement After 90 Days Of Treatment

Gain Therapeutics, Inc. (NASDAQ:GANX) ("Gain", or the "Company"), a clinical-stage biotechnology company leading the discovery and development of the next generation of allosteric small molecule therapies, today provided evidence, for the first time in Parkinson's Disease (PD), of a reduction in glucocerebrosidase (GCase) substrate in cerebrospinal fluid (CSF).

Decreased GluSph in CSF is an indication of increased GCase activity in the brain

All individuals with elevated levels of glucosylsphingosine (GluSph) in the CSF displayed large decreases back towards levels observed in healthy individuals after 90 days of treatment with GT-02287. Importantly, the change observed in GluSph in CSF was a prespecified exploratory endpoint of this Phase 1b study. Elevated GluSph, a hallmark of GCase dysfunction, has been shown to increase the aggregation of alpha synuclein and to impair mitochondrial function and other intracellular processes in neurons.

Gene Mack, president and CEO of Gain Therapeutics, commented on the results, stating, "We are excited by the unfolding biomarker evidence of GT-02287 activity and central nervous system target engagement. To our knowledge, GT-02287 is the first GCase modulator to demonstrate a reduction of GluSph in CSF in people with PD, providing downstream evidence of GCase enhancement in the brain. Further, we believe that reduction in brain GluSph levels will have a direct impact on neuronal health and translate to clinically observable improvements."

Mr. Mack continued, "With a capital position sufficient to fund operations through the end of the Phase 1b extension and year-end 2026, we look forward to presenting longer follow-up from the study at the AD/PD™ conference in March 2026, observing the effect of GT-02287 treatment on MDS-UPDRS scores in the participants who continued in the nine-month extension, and determining the durability of some of the anecdotal signs of early functional improvement."

GT-02287 Phase 1b Study

Part 1 (90 days of dosing) of the ongoing Phase 1b study has concluded. The Phase 1b study enrolled 21 participants; 19 completed the 90-day dosing period, and 15 (79%) chose to continue in the nine-month extension (Part 2) portion of the study that is anticipated to conclude in September 2026.

Consistent with the initial Phase 1b data presented at the International Congress of Parkinson's Disease and Movement Disorders in October 2025, GT-02287 continues to be generally well-tolerated over 90 days of dosing at plasma exposures within the projected therapeutic range. The data monitoring committee (DMC) has recommended that the Phase 1b study continue with no changes.

Upcoming Virtual KOL Event on GT-02287

Gain Therapeutics will host a webinar "Understanding GCase Substrates in Parkinson's Disease: Perspectives on Biomarkers and Disease Modification, Contextualizing emerging biomarker data from the Phase 1b clinical study of GT-02287", featuring key opinion leaders Roy Alcalay, M.D., M.Sc., and Peter Lansbury, Ph.D., on Tuesday, January 6, 2026 at 10:00 a.m. ET to discuss the results announced today and host a question-and-answer session. Additional details about the event will be issued closer to the event in a separate press release. To register, please click here.