NCT07181837

A Phase 1/2 Study of the Safety and Efficacy of MVX-220 in Angelman Syndrome

A Multi-Center, Open-label, Phase 1/2 Trial of the Safety and Efficacy of MVX-220 Gene Therapy Administered by Intra-Cisterna Magna Injection to Participants With Angelman Syndrome

• Status: Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 12 (estimated)
• Sponsor: MavriX Bio, LLC · Industry
• Sex: All
• Age: 4 Years – 50 Years
• Healthy volunteers: Not accepted

Summary

The purpose of this study is to evaluate the safety and efficacy of MVX-220 gene therapy in children and adults with Angelman syndrome with UBE3A gene deletion, uniparental disomy, or imprinting center defect genotypes.

Detailed description

MVX-220 is an investigational gene replacement therapy intended to provide a functional copy of the UBE3A gene to individuals with Angelman syndrome. This study is designed to evaluate the safety, tolerability and efficacy of MVX-220 in participants with Angelman syndrome who have deletion, uniparental disomy, or imprinting center disorder genotypes. The study has 2 primary cohorts: Cohort 1 that includes adults followed by Cohort 2 that includes children. All patients will receive a single dose of MVX-220 administered by injection into the cisterna magna. There is no control group and all individuals will receive the gene therapy. An independent data safety monitoring board will review the safety information from Cohort 1 before individuals can be enrolled in Cohort 2. An optional cohort of adults and/or children (Cohort 3) may be enrolled based on a review of data from Cohorts 1 and 2. All patients will be required to take steroids before and for a brief period during the study to help mitigate the risk of immune response to the gene therapy. Patients will be followed for safety and efficacy for an initial 2-year period post-treatment and then transition to less frequent monitoring schedule for an additional 3 years. The total duration of follow up in the study is 5 years.

Conditions

• Angelman Syndrome

Interventions

Type	Name	Description
GENETIC	MVX-220	AAVhu68 viral vector

Timeline

• Start date: 2025-10-29
• Primary completion: 2028-03-31
• Completion: 2031-05-31
• First posted: 2025-09-18
• Last updated: 2026-03-16

Locations

3 sites across 1 country: United States

Regulatory

• FDA-regulated drug study