Ultragenyx Pharmaceutical Inc. has received Breakthrough Therapy Designation from the U.S. Food and Drug Administration (FDA) for their drug GTX-102 (apazunersen) as a treatment for Angelman syndrome. This designation, aimed at expediting the development and review of drugs for serious or life-threatening diseases, is based on positive preliminary clinical evidence from a Phase 1/2 study involving 74 patients. The study showed consistent developmental gains and improvements across multiple symptom domains in participants treated for up to three years. Enrollment for the global Phase 3 Aspire study, which began in December 2024, is on track to complete in 2025, while the Aurora study is expected to start later this year to evaluate GTX-102 in other Angelman syndrome genotypes and ages.