Ultragenyx Announces First Patient Dosed in Aurora Study Evaluating GTX-102 in Additional Angelman Syndrome Genotypes and Age Groups

NOVATO, Calif., Oct. 30, 2025 (GLOBE NEWSWIRE) -- Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) today announced that the first patient has been dosed in the Aurora study (NCT07157254) evaluating the efficacy and safety of GTX-102 (apazunersen), an investigational antisense oligonucleotide (ASO) for Angelman syndrome (AS). Data from the Aurora study will expand the population of Angelman patients treated to include both younger and older patients and those with other non-deletion AS genotypes not included in the Phase 3 Aspire study. The fully enrolled Phase 3 Aspire study (NCT06617429) of GTX-102 is focused on patients aged 4 to 17 years with a genetically confirmed diagnosis of full maternal UBE3A gene deletion.

"The open-label basket design of the Aurora study will enable us to efficiently evaluate the safety and efficacy of GTX-102 in younger and older patients with Angelman syndrome and those with other genotypes," said Eric Crombez, M.D., chief medical officer at Ultragenyx. “While the Aspire study population represents the largest group of Angelman patients, we recognize the importance of bringing this potential new treatment to all patients, across genotypes and ages, as quickly as possible.”

Amanda Moore, chief executive officer at the Angelman Syndrome Foundation (ASF) and Ryan Fischer, chief operating officer at Foundation for Angelman Syndrome Therapeutics (FAST), added in a joint statement: "The launch of the Aurora trial marks an exciting and hopeful moment for the Angelman syndrome community. This study captures a broad spectrum of individuals living with Angelman syndrome and reflects a collective goal shared by our community—to ensure that clinical trial opportunities are available across ages and genotypes. We are grateful to Ultragenyx for their continued commitment to advancing research for our loved ones and for recognizing the importance of including a diverse population of individuals in clinical trials."

The global Aurora study will enroll approximately 60 participants ages 1 to < 65 with Angelman syndrome across all genotypes and will include some additional countries or regions that could not be included in the Aspire Phase 3 study. Participants will be assigned to one of four cohorts with corresponding subprotocols: