NCT07135050

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

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
12

participants targeted

Target at below P25 for phase_1

Timeline
38mo left

Started Dec 2025

Typical duration for phase_1

Geographic Reach
1 country

3 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress11%
Dec 2025Jul 2029

First Submitted

Initial submission to the registry

August 4, 2025

Completed
17 days until next milestone

First Posted

Study publicly available on registry

August 21, 2025

Completed
4 months until next milestone

Study Start

First participant enrolled

December 19, 2025

Completed
3.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 1, 2029

Expected
4 months until next milestone

Study Completion

Last participant's last visit for all outcomes

July 1, 2029

Last Updated

February 23, 2026

Status Verified

February 1, 2026

Enrollment Period

3.2 years

First QC Date

August 4, 2025

Last Update Submit

February 20, 2026

Conditions

Pitt Hopkins Syndrome

Keywords

MZ-1866AAV9 Gene TherapyGene TherapyICVIntracerebroventricularTCF4PTHS

Outcome Measures

Primary Outcomes (1)

  • To evaluate the safety and tolerability of MZ-1866 in participants with Pitt Hopkins Syndrome

    Frequency and severity of adverse events of special interest

    Week 104

Secondary Outcomes (2)

  • To evaluate the safety and tolerability of MZ-1866 in participants with Pitt Hopkins Syndrome

    Week 104

  • To further assess the safety and tolerability of MZ-1866 in participants with Pitt Hopkins Syndrome

    Week 104

Study Arms (2)

Cohort 1 (MZ-1866)

EXPERIMENTAL

Participants ages 12-25 years

Genetic: MZ-1866

Cohort 2 (MZ-1866)

EXPERIMENTAL

Participants aged 2-11 years

Genetic: MZ-1866

Interventions

MZ-1866GENETIC

AAV-9 gene therapy delivered by intracerebroventricular injection

Cohort 1 (MZ-1866)Cohort 2 (MZ-1866)

Eligibility Criteria

Age2 Years - 25 Years
Sexall
Healthy VolunteersNo
Age GroupsChild (0-17), Adult (18-64)

You may qualify if:

  • 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

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (3)

UCSF Benioff Children's Hospital Oakland

Oakland, California, 94609, United States

RECRUITING

Children's Hospital Colorado

Aurora, Colorado, 80045, United States

RECRUITING

Rush University Medical Center

Chicago, Illinois, 60612, United States

NOT YET RECRUITING

MeSH Terms

Conditions

Pitt-Hopkins syndrome

Central Study Contacts

Emily Radomile

CONTACT

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

Study Design

Study Type
interventional
Phase
phase 1
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
SEQUENTIAL
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

August 4, 2025

First Posted

August 21, 2025

Study Start

December 19, 2025

Primary Completion (Estimated)

March 1, 2029

Study Completion (Estimated)

July 1, 2029

Last Updated

February 23, 2026

Record last verified: 2026-02

Locations

US(3)