Clinical-stage biotechnology company MavriX Bio and AS2Bio, a drug development accelerator established by the Foundation for Angelman Syndrome Therapeutics (FAST), announced on Thursday that the first patient has been dosed in the Phase 1/2 ASCEND-AS clinical trial of MVX-220, an investigational gene therapy for Angelman syndrome (AS).

The ASCEND-AS trial represents the first clinical evaluation of a gene therapy for AS.

Supported by FAST and AS2Bio, MavriX Bio developed MVX-220 to restore functional expression of the UBE3A gene in neurons using targeted AAV delivery to the central nervous system. The trial will evaluate safety, tolerability, and efficacy of MVX-220 in both adult and paediatric participants with different AS genotypes, including deletion, uniparental disomy, and imprinting centre defects.

MavriX Bio also announced that the US Food and Drug Administration (FDA) has granted Orphan Drug Designation for MVX-220 for treatment of AS.

AS affects approximately 1 in 12,000 to 20,000 individuals worldwide and currently has no approved disease-modifying treatments.