RecruitingPhase 1Phase 2NCT07181837

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

Sponsor

MavriX Bio, LLC

Enrollment

12 participants

Start Date

Oct 29, 2025

Study Type

INTERVENTIONAL

Conditions

Angelman Syndrome

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.

Eligibility

Min Age: 4 YearsMax Age: 50 Years

Inclusion Criteria8

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).

Exclusion Criteria21

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.
Current therapy with high dose immunosuppressants.
Prior or current treatment with an investigational drug within 6 months or 5-half-lives of the hospital admission whichever is longer.
Prior treatment with an antisense oligonucleotide within 1 year of hospital admission.
A history of gene therapy administration.
Any contraindication to ICM administration procedure, including contraindications to imaging, contrast use, anesthesia, or any condition that would increase the risk of adverse outcomes from the ICM procedure.
Any contraindication to glucocorticoid use