Enrollment Complete in Global Phase 1/2 GTX-102 Trial for Pediatric Angelman Syndrome

Ultragenyx Pharmaceutical, a company dedicated to developing treatments for rare genetic disorders, has achieved a significant milestone in its clinical trial for GTX-102, a potential therapy for children with Angelman syndrome (AS). The Phase 1/2 trial has successfully enrolled 74 patients globally, with 53 participants in the dose-expansion cohorts. GTX-102 is an innovative antisense oligonucleotide, administered directly into the spinal fluid, targeting the UBE3A antisense transcript (UBE3A-AS) to reduce its expression.

Eric Crombez, Ultragenyx's chief medical officer, expressed optimism about the trial's progress and the anticipated results in the first half of 2024. He highlighted the importance of the Angelman community's support in the development of this life-enhancing treatment. Preliminary data from the ongoing study have shown positive improvements in various areas, with no additional serious treatment-related adverse events reported since November 2022.

The Phase 1/2 study is an open-label, multiple-dose, escalating dose trial that assesses the safety and tolerability of GTX-102 in pediatric patients with genetically confirmed full maternal UBE3A gene deletion. It also evaluates the clinical response through a set of efficacy assessments focused on the functional domains affected by AS. Participants from the earlier extension cohorts have transitioned into long-term maintenance dosing, and the trial aims to confirm the appropriate dose range and treatment regimen for the subsequent Phase 3 program.

Angelman syndrome is a neurogenetic disorder characterized by developmental delays, motor impairments, and seizures, often resulting in individuals being unable to walk or speak. Despite having a normal lifespan, those with AS require continuous care and cannot live independently. The syndrome is caused by the loss of function of the maternal UBE3A gene, with the paternal UBE3A gene being silenced due to genomic imprinting. GTX-102 is designed to reactivate the expression of the paternal UBE3A allele, potentially leading to improvements in neurological symptoms.

GTX-102 has received several designations from the FDA, including Orphan Drug, Rare Pediatric Disease, and Fast Track, reflecting its potential significance for treating a condition with no approved therapies. The company is committed to advancing the development of GTX-102, with the aim of providing a new treatment option for those affected by Angelman syndrome.