MavriX Bio Receives FDA Clearance for Angelman Syndrome Gene Therapy

MIDDLETON, MA – May 12, 2025 – MavriX Bio, a biotechnology company focused on genetic therapies for Angelman syndrome (AS), announced today that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application for MVX-220. This investigational adeno-associated virus (AAV) gene therapy is designed to restore the function of the UBE3A gene in neurons, which is the underlying cause of AS.

MavriX Bio plans to initiate the “ASCEND-AS” first-in-human (FIH) clinical study of MVX-220 in the latter half of 2025. This study will assess the safety, tolerability, and efficacy of MVX-220 in both adult and pediatric individuals with various genetic subtypes of Angelman syndrome.

Allyson Berent, DVM, DACVIM, Chief Development Officer of MavriX Bio, expressed excitement about this milestone, stating it brings them closer to providing the first gene therapy for Angelman syndrome.

MVX-220’s development was supported by the Foundation for Angelman Syndrome Therapeutics (FAST) and subsequently licensed to MavriX Bio, a portfolio company of FAST’s drug development accelerator AS2Bio. GEMMABio, a therapeutics company focused on gene therapy development and global access, is collaborating on this effort. Jim Wilson, MD, PhD, President and CEO of GEMMABio, highlighted the decades of collaboration and scientific innovation that led to this point, offering renewed hope for families affected by Angelman syndrome.

MavriX Bio will host a webinar with details on the clinical trial design, eligibility, and timelines in the coming months. Information on registration will be available through FAST and the Angelman Syndrome Foundation.

About Angelman Syndrome: AS is a rare neurological disorder characterized by developmental delay, lack of speech, sleep disturbances, seizures, and motor impairments, affecting an estimated 1 in 12,000 to 1 in 20,000 individuals. Currently, there are no approved treatments.

About MVX-220: This investigational gene therapy aims to deliver the human UBE3A gene to brain neurons via a single intra-cisterna magna (ICM) injection. Preclinical studies have shown its ability to restore UBE3A protein expression and alleviate AS symptoms in a mouse model. The ASCEND-AS Phase 1/2 trial will now evaluate its potential in humans.