An Open-label Extension Safety Study of MELAS Patients Who Completed TIS6463-203 (PRIZM)

The goal of this clinical trial is to evaluate the long-term safety and tolerability of zagociguat in patients with MELAS who completed study medication treatment in the lead-in study TIS6463-203. TIS6463-204 is evaluating zagociguat in an open-label extension study at the daily dose of 15mg. The study medication is a once daily oral table and will be provided at the clinic and/or shipped to the participant's home. Study assessments will be conducted during clinic visits which will occur at three months and then at six months. Thereafter, clinic visits will occur every six months.

NCT Number	NCT06961344
Lead Sponsor	Tisento Therapeutics
Conditions	Mitochondrial Encephalopathy, Lactic Acidosis and Stroke-Like Episodes (MELAS Syndrome)
Enrollment	44 participants
Start Date	2025-08-18
Primary Completion	2028-07 (estimated)
Study Completion	2028-07 (estimated)
Updated on ClinicalTrials.gov	2026-07-07