Biogen's Alzheimer's Drug Diranersen Shows Robust Tau Reduction and Cognitive Benefit in Phase 2
BIIB sits 72% above its 52-week low of $121.05 on elevated volume (1.9× avg).
Summary
Biogen presented detailed Phase 2 CELIA data for tau-targeting Alzheimer's drug diranersen at AAIC 2026. The 60 mg dose showed a 26% slowing of clinical decline on CDR-SB and 42% on ADAS-Cog13 versus placebo, with nominal statistical significance. Biomarker data revealed 50-65% CSF total tau reduction and tau PET decreases across brain regions—a first for a tau therapy. Safety was manageable, with mostly mild to moderate adverse events. This expands on May's topline results and Phase 3 advancement decision, adding concrete efficacy and biomarker evidence that strengthens the case for late-stage development. The data provide proof of concept for tau reduction translating to clinical benefit, a key differentiator in the Alzheimer's space. Phase 3 planning is underway, with regulatory discussions expected.
At the time of this announcement, BIIB was trading at $208.20 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $30.9B. The 52-week trading range was $121.05 to $219.72. This news item was assessed with positive market sentiment and an importance score of 8 out of 10. Source: GlobeNewswire.