Ionis announces positive detailed results from the HALOS Study of ION582 in people with Angelman syndrome

Core Insights - Ionis Pharmaceuticals announced positive results from the Phase 1/2 study of ION582 for Angelman syndrome, showing significant clinical improvements in communication, cognition, and motor function [1][2][3] - 97% of patients in the medium and high dose groups experienced improvement in overall Angelman syndrome symptoms as measured by the SAS-CGI-C [1][3] - Ionis plans to initiate Phase 3 development of ION582 in the first half of 2025 [1][2][4] Study Results - The HALOS study included 51 participants aged 2 to 50, demonstrating consistent benefits across all ages and genotypes [3][7] - Improvements in key functional areas exceeded those observed in natural history studies, with significant enhancements noted in the Bayley-4 assessments [3][4] - The study reported favorable safety and tolerability for ION582 at all dose levels [1][3] Assessment Tools - The study utilized various assessment tools, including Bayley-4, Vineland-3, ORCA, and SAS-CGI-C, to evaluate improvements in cognition, communication, and motor function [4][5] - Specific improvements included: - Cognition: 67% improvement on Bayley-4 - Receptive Communication: 67% on Bayley-4, 89% on Vineland-3 - Expressive Communication: 69% on Bayley-4, 84% on Vineland-3 - Gross Motor: 46% on Bayley-4, 53% on Vineland-3 - Fine Motor: 72% on Bayley-4, 63% on Vineland-3 - Daily Living Skills: 74-82% on Vineland-3 [5][6] Future Plans - Ionis intends to meet with regulators to confirm the Phase 3 study design later this year, aiming for a pivotal study initiation in H1 2025 [4][7] - The company is focused on developing transformative medicines for neurological conditions, with ION582 positioned as a cornerstone of its future pipeline [2][10]