Gain Therapeutics shares surge 16.44% premarket after Phase 1b trial shows first-ever GluSph reduction in Parkinson’s CSF, indicating CNS target engagement.

Gain Therapeutics surged 16.44% in premarket trading following the release of positive Phase 1b clinical trial results for its Parkinson’s disease candidate GT-02287. The study demonstrated a first-ever reduction in glucosylsphingosine (GluSph) levels in cerebrospinal fluid (CSF) after 90 days of treatment, indicating central nervous system (CNS) target engagement and increased GCase activity. This biomarker evidence, coupled with 79% of participants entering a nine-month extension and strong tolerability, underscores the drug’s disease-modifying potential. The company also announced a January 2026 virtual KOL event with leading neurologists to discuss the findings, further boosting investor optimism. CEO Gene Mack highlighted the significance of the results, emphasizing potential clinical improvements in neuronal health and disease progression. These developments align with the stock’s sharp premarket rise, reflecting market confidence in the therapy’s prospects.