Healthcare
Biogen Presents Phase 2 CELIA Data at AAIC Demonstrating Meaningful Clinical Outcomes and Robust Tau Reduction with Diranersen in Early Alzheimer’s Disease
Clinical outcomes: Diranersen demonstrated efficacy across all studied doses at 18 months, with consistent results across multiple prespecified clinical endpoints; the 60 mg dose showed the strongest response with slowing of clinical decline on the cognitive endpoints—42% on ADAS-Cog13 and 50% on MMSE—alongside a 26% slowing on CDR-SBBiomarker response: Diranersen is the first tau-directed therapy to demonstrate robust reductions in both CSF total tau, with mean reductions of 50–65%, and brain t
About this update from Biogen Inc.
CAMBRIDGE, Mass., July 14, 2026 (GLOBE NEWSWIRE) -- Biogen Inc. (Nasdaq: BIIB) today announced data from the Phase 2 CELIA study evaluating diranersen, an investigational antisense oligonucleotide (ASO) therapy targeting tau, in individuals with early Alzheimer's disease. The data, presented at the Alzheimer's Association International Conference (AAIC) 2026, expand upon previously reported topline results and demonstrate a combination of meaningful clinical efficacy and robust biomarker effects, providing Phase 2 proof of concept for diranersen's tau-directed mechanism of action. Based on the growing and consistent body of evidence from the Phase 1b and Phase 2 studies, Biogen plans to advance diranersen into confirmatory Phase 3 development.1 "The CELIA data provide some of the clearest evidence that reducing tau pathology can translate into clinically meaningful benefit," said Professor Cath Mummery, Professor of Clinical Neurology at the UCL Queen Square Institute of Neurology and Consultant Neurologist at University College London Hospitals NHS Foundation Trust. "The magnitude of tau reduction and cognitive benefit observed in CELIA is among the most compelling reported to date in Alzheimer's disease drug development and supports advancing diranersen to Phase 3 development." "The CELIA clinical, biomarker, and safety data presented at AAIC provide proof of concept and important evidence of diranersen's novel tau-reduction mechanism of action translating into clinical benefit. If confirmed in Phase 3, diranersen could represent an important new therapeutic approach targeting one of the core pathologies of Alzheimer's disease," said Priya Singhal, M.D., M.P.H., Executive Vice President and Head of Development at Biogen. "Patients and families urgently need new approaches that address the complexity of Alzheimer's disease. We look forward to working with health authorities and the broader Alzheimer's community as diranersen advances to Phase 3."