Phase 3 Aspire study enrollment on track to complete in 2025
Aurora study to evaluate GTX-102 in other Angelman syndrome genotypes and ages expected to initiate later this year
June 27, 2025 -- Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE), today announced that it has received Breakthrough Therapy Designation from the U.S. Food and Drug Administration (FDA) for GTX-102 (apazunersen) as a treatment for Angelman syndrome.
"FDA Breakthrough Therapy Designation underscores both the urgent need for an effective treatment for patients and families affected by Angelman syndrome and the clinically meaningful results demonstrated to date with GTX-102,” said Eric Crombez, M.D., chief medical officer at Ultragenyx. "Based on the strength of the Phase 2 data and with strong support and interest from the Angelman syndrome community, our Phase 3 Aspire study is rapidly enrolling across our global sites. We look forward to advancing GTX-102 through the development process as rapidly as possible to bring this potential treatment to patients.”
The FDA’s decision is based on preliminary clinical evidence including positive data from the Phase 1/2 study in 74 patients (4-17 years of age) with a full maternal UBE3A gene deletion, that showed participants have made consistent developmental gains with rapid, sustained and continuing improvements across multiple symptom domains when treated for up to 3 years. Breakthrough Therapy Designation aims to expedite the development and review of drugs that are intended to treat serious or life-threatening diseases and whose preliminary clinical evidence indicates that the drug may demonstrate substantial improvement on one or more clinically significant endpoints over existing therapies.
Enrollment in the global Phase 3 Aspire study (NCT06617429) began in December 2024 and is expected to enroll approximately 120 children ages four to 17 with Angelman syndrome with a genetically confirmed diagnosis of full maternal UBE3A gene deletion. The Aurora study will evaluate GTX-102 across other Angelman syndrome genotypes and ages and is expected to initiate in the second half of 2025.
GTX-102 (apazunersen) is an investigational antisense oligonucleotide (ASO) therapy delivered via intrathecal administration and designed to target and inhibit expression of the UBE3A antisense transcript (UBE3A-AS) to prevent silencing of the paternally inherited allele of the UBE3A gene and reactivate expression of the deficient protein. GTX-102 has been granted Breakthrough Therapy Designation, Orphan Drug Designation, Rare Pediatric Disease Designation, and Fast Track Designation from the FDA and Orphan Designation and PRIME designation from the EMA.
Angelman syndrome is a rare, neurogenetic disorder caused by loss-of-function of the maternally inherited allele of the UBE3A gene. The maternal-specific inheritance pattern of Angelman syndrome is due to genomic imprinting of UBE3A in neurons of the central nervous system (CNS), a naturally occurring phenomenon in which the maternal UBE3A allele is expressed and the paternal UBE3A is not. Silencing of the paternal UBE3A allele is regulated by the UBE3A-AS, the intended target of GTX-102. In almost all cases of Angelman syndrome, the maternal UBE3A allele is either missing or mutated, resulting in limited to no protein expression. This condition is generally not inherited but instead occurs spontaneously. It is estimated to affect approximately 60,000 people in commercially accessible geographies.
Angelman syndrome is a lifelong neurodevelopmental disorder that causes cognitive impairment, motor impairment, balance issues and debilitating seizures. Some individuals with Angelman syndrome are unable to walk and most do not speak. Anxiety and disturbed sleep can be serious challenges in individuals with Angelman syndrome. Although individuals with Angelman syndrome have a normal lifespan, they require continuous care and are unable to live independently. Angelman syndrome is not a degenerative disorder, but the loss of the UBE3A protein expression in neurons results in abnormal communications between neurons. Angelman syndrome is often misdiagnosed as autism or cerebral palsy. There are no currently approved therapies for Angelman syndrome; however, several symptoms of this disorder can be reversed in adult animal models of Angelman syndrome, suggesting that improvement of symptoms can potentially be achieved at any age.
Ultragenyx is a biopharmaceutical company committed to bringing novel therapies to patients for the treatment of serious rare and ultra-rare genetic diseases. The company has built a diverse portfolio of approved medicines and treatment candidates aimed at addressing diseases with high unmet medical need and clear biology, for which there are typically no approved therapies treating the underlying disease.
The company is led by a management team experienced in the development and commercialization of rare disease therapeutics. Ultragenyx’s strategy is predicated upon time- and cost-efficient drug development, with the goal of delivering safe and effective therapies to patients with the utmost urgency.
The content above comes from the network. if any infringement, please contact us to modify.
