Recruiting
Phase 1
Phase 2

MZ-1866

Sponsor:

Mahzi Therapeutics

Code:

NCT07135050

Conditions

Pitt Hopkins Syndrome

Eligibility Criteria

Sex: All

Age: 2 - 25

Healthy Volunteers: Not accepted

Interventions

MZ-1866

Study Details

Brief summary:

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

Conditions

Pitt Hopkins Syndrome

Study ID

NCT07135050

Start date

Dec 19, 2025

Status verified date

Jul, 2026

Completion date

Jul, 2029

Anticipated

Primary completion date

Mar, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 2 - 25

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • The participant has a TCF4 gene mutation confirmed as "pathogenic" or "likely pathogenic" by whole exome sequencing, whole genome sequencing, gene panel, single gene testing, or microarray, performed at an accredited laboratory
  • Clinical phenotype consistent with Pitt Hopkins Syndrome, in the opinion of the investigator
  • The participant, or the participant's parent or legal guardian, is willing to provide access to prior medical records for the collection of demographics and diagnostic and treatment history

Exclusion Criteria:

  • A deletion that includes the TCF4 gene that is over 12 Mbp in size
  • Another genetic mutation or clinical comorbidity not associated with Pitt Hopkins Syndrome that could potentially confound interpretation of the study data
  • A central nervous system structural or vascular abnormality that is a contraindication to the ICV administration procedure, including but not limited to: signs or symptoms of increased intracranial pressure, history of a space-occupying lesion, or presence of a ventricular shunt that would preclude ICV procedures or safety assessments, or increase risk to the participant
  • Not able to receive prophylactic corticosteroids due to a medical contraindication or participant has a history of a condition that could worsen with corticosteroid therapy as assessed and determined by the Investigator
  • Not able to undergo MRI procedures
  • Cannot be anesthetized for the ICV injection

Study Design

Enrollment

12 participants

Anticipated

Allocation

Non randomized

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Cohort 1 (MZ-1866)

Participants ages 12-25 years

experimental: Cohort 2 (MZ-1866)

Participants aged 2-11 years

Interventions

MZ-1866

AAV-9 gene therapy delivered by intracerebroventricular injection

Primary outcome measure

  • To evaluate the safety and tolerability of MZ-1866 in participants with Pitt Hopkins Syndrome [ Time Frame: Week 104 ]

Central Contacts and Locations

Central contacts

Emily Radomile

1-844-446-2494clinicaltrials@mahzi.com

Locations

UCSF Benioff Children's Hospital Oakland

Recruiting

Oakland, California, United States, 94609

Contacts

Neil Smith

neil.smith2@ucsf.edu

Principal Investigator:

Alex Fay, M.D., Ph.D.

Children's Hospital Colorado

Recruiting

Aurora, Colorado, United States, 80045

Contacts

Sky Gould

sky.gould@childrenscolorado.org

Principal Investigator:

Diana Walleigh, MD

Rush University Medical Center

Recruiting

Chicago, Illinois, United States, 60612

Contacts

Tara Khandelwal

Mehr_Khandelwal@rush.edu

Principal Investigator:

Elizabeth Berry-Kravis, M.D., Ph.D.

More Information

Sponsor

Mahzi Therapeutics

Last update posted

Jul 31, 2026

Last verified

Jul, 2026

Keywords

  • MZ-1866
  • AAV9 Gene Therapy
  • Gene Therapy
  • ICV
  • Intracerebroventricular
  • TCF4
  • PTHS

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Mahzi Therapeutics on 2026-07-31.