RecruitingPhase 1/2

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

United States12 participantsStarted 2025-10-29

Plain-language 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.

Who can participate

Age range

4 Years – 50 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. 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 criteria

. 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:

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

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

Timeframe: Up to Week 104

Trial details

NCT IDNCT07181837

SponsorMavriX Bio, LLC

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2028-03-31

Contact for this trial

MavriX Bio, LLC

978-538-8554 info@mvxbio.com

View on ClinicalTrials.gov More Angelman Syndrome trials