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

NCT07181837 | Recruiting Phase 1 DMC FDA Drug

• 1 other identifier: MVX-AAV-101
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 3

Brief 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.

Conditions

Angelman Syndrome

Keywords

Angelman syndrome; gene therapy; AAV; cisterna magna

Outcome Measures

Primary Outcomes (1)

• Incidence of Adverse Events, Serious Adverse Events, and Adverse Events of Special Interest as assessed through clinical safety, laboratory tests, ECG, vital sign measurements, and physical examinations

  Up to Week 104

Secondary Outcomes (11)

• Change in communication ability as assessed by the Observer Reported Communication Ability (ORCA) measure

  From Baseline to Week 104

• Change in developmental milestones as assessed by the Bayley Scale of Infant and Toddler Development, Fourth Edition (Bayley-4)

  From Baseline to Week 104

• Change in adaptive behaviors as assessed by Vineland Adaptive Behavior Scale (VABS-3)

  From Baseline to Week 104

• Change in Symptoms by the Angelman Severity Assessment (ASA)

  From Baseline to Week 104

• Change in behaviors as assessed by the Aberrant Behavior Checklist-Community (ABC-C)

  From Baseline to Week 104

Study Arms (3)

Cohort 1: Adults ages 18-50

EXPERIMENTAL

MVX-220, single dose intra cisterna magna injection

Genetic: MVX-220

Cohort 2: Children ages 4-8

EXPERIMENTAL

MVX-220, single dose intra cisterna magna injection

Genetic: MVX-220

Cohort 3: Optional cohort, adults and children ages 4-50

EXPERIMENTAL

MVX-220, single dose intra cisterna magna injection

Genetic: MVX-220

Interventions

MVX-220 GENETIC

AAVhu68 viral vector

Cohort 1: Adults ages 18-50; Cohort 2: Children ages 4-8; Cohort 3: Optional cohort, adults and children ages 4-50

Eligibility Criteria

• Age: 4 Years - 50 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• The participant's parent/legal guardian must provide written informed consent.
• Symptoms consistent with AS and documented genetic confirmation of one of the following genotypes resulting in a diagnosis of AS:
• Full maternal UBE3A gene deletion causing AS in the region of 15q11.2-q13
• Uniparental disomy
• Imprinting center defect
• The participant must be 18 to 50 years of age, inclusive (for adult participants), or 4 to 8 years of age, inclusive (for pediatric participants), at Screening.
• The participant must have the ability to ambulate independently.
• The participant must be on stable antiepileptic medications (with no changes within 1 month prior to the Screening visit, except for weight associated dose adjustments).

You may not qualify if:

• Clinically significant medical finding other than AS, that, in the judgment of the Investigator would make the participant unsuitable for participation.
• Laboratory abnormalities including but not limited to:
• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) \> upper limit of normal (ULN)
• Total and/or fractionated bilirubin (direct and/or indirect) \> ULN
• Gamma-glutamyl transferase (GGT) \> ULN
• Estimated glomerular filtration rate (eGFR) below the lower limit of normal (LLN) for age
• Hemoglobin \< 8 g/dL
• White blood cell (WBC) count outside the normal range for age
• Platelet count \< LLN
• Partial thromboplastin time (PTT) outside the reference range
• PT/International normalized ratio (INR) outside the reference range
• Any known history and/or family history of hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS) or multisystem inflammatory syndrome (MIS).
• Any known history and/or family history of disordered complement function and/or complement gene mutation(s).
• History of systemic lupus erythematous, Still's disease, rheumatoid arthritis, and/or other severe autoimmune conditions per judgment of the Investigator.
• Any known history of thrombotic microangiopathy (TMA)/microangiopathic hemolytic anemia, or hypercoagulable conditions including, but not limited to, disseminated intravascular coagulation (DIC), deep venous thrombosis, and pulmonary embolism.

Sponsors & Collaborators

• MavriX Bio, LLC: lead

Study Sites (3)

Cedars-Sinai Medical Center

Los Angeles, California, 90048, United States

RECRUITING

Rush University Medical Center

Chicago, Illinois, 60612, United States

RECRUITING

Boston Children's Hospital

Boston, Massachusetts, 02115, United States

RECRUITING

MeSH Terms

Conditions

Angelman Syndrome

Condition Hierarchy (Ancestors)

Movement Disorders; Central Nervous System Diseases; Nervous System Diseases; Abnormalities, Multiple; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Chromosome Disorders; Genetic Diseases, Inborn; Imprinting Disorders

Central Study Contacts

MavriX Bio, LLC

CONTACT

978-538-8554; info@mvxbio.com

Study Design

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

Study Record Dates

• First Submitted: September 6, 2025
• First Posted: September 18, 2025
• Study Start: October 29, 2025
• Primary Completion (Estimated): March 31, 2028
• Study Completion (Estimated): May 31, 2031
• Last Updated: March 16, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (3)