Gain Therapeutics Announces 12-Month Phase 1b OLE Data for Rexaceract

What Happened

• On October 1, 2026 Gain Therapeutics (GANX) filed an 8‑K and issued a press release reporting poster presentation at the International Congress of Parkinson’s Disease and Movement Disorders (Oct 4–8, 2026, Seoul). The poster summarizes long‑term open‑label extension (OLE) results from the Phase 1b study of rexaceract in Parkinson’s disease (PD), showing stabilization of Movement Disorder Society‑sponsored Revision of the Unified Parkinson’s Disease Rating Scale (MDS‑UPDRS) scores over 360 days (12 months) of dosing. As of August 31, 2026, 12 of 13 evaluable patients completed the full 12‑month OLE (one scheduled to finish dosing in Nov 2026). The company said no new safety signals were observed and overall treatment‑emergent adverse events were lower in the nine‑month extension than in the initial three‑month part of the study.

Key Details

• Poster presented at the International Congress of Parkinson’s Disease and Movement Disorders (Oct 4–8, 2026) in Seoul.
• 12 of 13 evaluable participants completed 12 months of rexaceract dosing as of Aug 31, 2026; one completes in Nov 2026.
• MDS‑UPDRS Parts II+III showed no clinically meaningful progression over 12 months; a clinically meaningful increase is ~6 points/year (the mean annual progression in early PD).
• Participants with both high and low baseline CSF glucosylsphingosine (GluSph) showed stabilized motor scores; those with high baseline GluSph experienced a marked decrease toward healthy levels by day 90. Company plans to submit a Phase 2 protocol to the FDA in the coming weeks and to initiate a Phase 2 trial in Q1 2027.

Why It Matters

• These OLE data provide early evidence of target engagement (reduced CSF GluSph) and 12‑month stabilization of motor scores in a small Phase 1b cohort, which the company says supports continued development of rexaceract and informed its planned Phase 2 submission. Safety data reported were consistent with prior results (no new safety signals; fewer adverse events in the extension).
• For investors, the filing outlines the next near‑term catalysts: a Phase 2 protocol submission to the FDA and anticipated Phase 2 trial start in Q1 2027. Note these are preliminary, open‑label results from a small study and the company included standard forward‑looking cautions in the 8‑K.