First Investigational Gene Therapy for Pitt Hopkins Syndrome Intended to Address Underlying Disease Biology

-- Mahzi Therapeutics Inc., a clinical-stage biotechnology company developing precision therapies for neurogenetic disorders,  announced that the first patient has been dosed in its Phase 1/2 UNITE study evaluating MZ-1866, an investigational gene therapy for the treatment of Pitt Hopkins syndrome.

The Phase 1/2 study is a global, multicenter, open‑label trial designed to assess the safety, tolerability, and preliminary efficacy of a single administration of MZ‑1866 in participants with genetically confirmed Pitt Hopkins syndrome. This rare condition, affecting approximately 1 in 34,000-41,000 individuals and translating to an estimated 8,000 people living with Pitt Hopkins in the Unites States, results from mutations in the TCF4 gene. Affected individuals present with a combination of autism, developmental delay, hypotonia, ataxia, apnea/hyperventilation, severe gastrointestinal issues, and, less frequently, epilepsy. MZ‑1866 aims to address the underlying disease biology by providing functional copies of the TCF4 gene.

"Dosing the first patient is a significant achievement for the MZ-1866 program and for Mahzi's evolution as a clinical-stage company," said Yael Weiss, M.D., Ph.D., Chief Executive Officer of Mahzi. "We look forward to advancing this program to address a significant unmet medical need for patients with Pitt Hopkins syndrome and their families."

"The launch of the first investigational gene therapy trial for Pitt Hopkins syndrome represents a truly historic milestone for our community," said Audrey Davidow, President of the Pitt Hopkins Research Foundation. "For families who have waited years for meaningful therapeutic progress, this moment reflects countless hours of advocacy, collaboration, and perseverance. This Phase 1/2 trial brings long-held hope closer to reality and marks a critical step toward transforming the future of care for individuals living with Pitt Hopkins."

MZ-1866 was developed in collaboration with the Muotri Lab at the University of California San Diego, and the Phase 1/2 study was made possible by funding from the California Institute for Regenerative Medicine (CIRM), a state of California Agency that funds regenerative medicine, stem cell, and gene therapy research (Grant Number TRAN1-13997).