Angelman syndrome stories

Sep 3, 2026

Ultragenyx's Angelman syndrome drug fails Phase 3 trial

Ultragenyx Pharmaceuticals' apazunersen did not meet the goals of its Phase 3 test in Angelman syndrome, a rare genetic neurological disorder with no FDA-approved therapies. The failure of what was once considered a potential blockbuster therapy is forcing Ultragenyx to examine significant cost cuts.

Sep 3, 20262 sources

Top claims

▪Leerink Partners analyst Joseph Schwartz suggested that the positive gains observed in the Phase 2 trial of apazunersen may have been due to natural developmental progression, practice effects, and expectation bias
▪Apazunersen is an antisense oligonucleotide designed to inhibit the long non-coding RNA that silences the paternal UBE3A gene, aiming to activate the gene to produce a key nervous system enzyme
▪Ultragenyx Pharmaceutical's experimental Angelman syndrome drug apazunersen, also known as GTX-102, failed to meet its primary and key secondary endpoints in the Phase 3 Aspire study

Subtopics

Clinical evaluation1 Clinical Trial Design & Evaluation1 Clinical trials1 Drug Approval and Clinical Trials1 Drug approval process1 Drug Policy, Pricing & Approval1 Fintech industry1 Neurological disorders1

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