Ultragenyx Receives FDA Breakthrough Therapy Designation for GTX-102 in Angelman Syndrome
Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) has been granted Breakthrough Therapy Designation by the United States Food and Drug Administration (FDA) for its investigational treatment GTX-102 (apazunersen) for Angelman syndrome.
The designation follows encouraging results from a Phase 1/2 clinical trial involving 74 children aged 4 to 17 with a confirmed full maternal UBE3A gene deletion.
Over a treatment period of up to three years, patients showed ongoing developmental progress with improvements across several areas of function.
The FDA’s Breakthrough Therapy Designation is intended to speed up the development and review of treatments for serious conditions where early data suggest a significant improvement over current options.
GTX-102 is an antisense oligonucleotide (ASO) therapy administered through the spinal canal. It is designed to block the UBE3A antisense transcript (UBE3A-AS), which normally silences the paternal copy of the UBE3A gene in nerve cells.
By inhibiting this transcript, GTX-102 aims to restore expression of the UBE3A protein from the paternal allele.
The therapy has already received multiple regulatory designations, including Orphan Drug, Rare Paediatric Disease, Fast Track, and now Breakthrough Therapy in the United States, as well as Orphan and PRIME designations in Europe.
Angelman syndrome is a rare neurogenetic disorder caused by the loss or mutation of the maternally inherited UBE3A gene. This gene is normally active only on the maternal side in neurons due to a process called genomic imprinting.
In people with Angelman syndrome, the absence of maternal UBE3A function and natural silencing of the paternal copy lead to a lack of protein expression in the brain.
