A Phase 1/2 Multiple-Ascending-Dose Study With a Long-Term Open-Label Extension to Assess the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Effect on Disease Progression of BIIB105 Administered Intrathecally to Adults With Amyotrophic Lateral Sclerosis With or Without Poly-CAG Expansion in the Ataxin-2 Gene

14375BIOGEN-275AS101-ALSPIREOpen (affiliates only)A Phase 1/2 Multiple-Ascending-Dose Study With a Long-Term Open-Label Extension to Assess the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Effect on Disease Progression of BIIB105 Administered Intrathecally to Adults With Amyotrophic Lateral Sclerosis With or Without Poly-CAG Expansion in the Ataxin-2 Gene275AS101NCT04494256IndustrialAdultTreatmentOtherStreicher, NicholasGeorgetown University Medical Center; Lombardi Comprehensive Cancer CenterGUMC Neurology2026.1.0 Build 16 <a href="https://advarra.com" target="_blank">© 2026 Advarra, Inc.</a>