Phase 1/2 Study of MZ-1866, an AAV-9 Gene Therapy Delivered by Intracerebroventricular Injection to Participants With Pitt Hopkins Syndrome

The goal of this clinical trial is to learn if MZ-1866 is a safe and tolerable treatment for children and adults with Pitt Hopkins Syndrome. To evaluate the safety of MZ-1866, the following will be evaluated: * frequency and severity of adverse events * physical exam, laboratory results and electrocardiogram findings Participants will: * receive a single dose of MZ-1866 by intracerebroventricular injection * be seen by the study physician and site staff periodically to assess changes to their health status * be periodically evaluated using neurodevelopmental tools Caregivers will: * be interviewed periodically about the health status and development of the participant * keep diaries and complete periodic questionnaires regarding participant symptoms

NCT Number	NCT07135050
Lead Sponsor	Mahzi Therapeutics Collaborators: California Institute for Regenerative Medicine (CIRM)
Conditions	Pitt Hopkins Syndrome
Enrollment	12 participants
Start Date	2025-12-19
Primary Completion	2029-03 (estimated)
Study Completion	2029-07 (estimated)
Updated on ClinicalTrials.gov	2026-07-31