Eisai Doubles Down on Tau as Alzheimer's R&D Broadens Beyond Amyloid
SHERIDAN, WYOMING - December 8, 2025 - Days after Johnson & Johnson reported a mid-stage failure for its anti-tau antibody posdinemab, Eisai is using the Clinical Trials on Alzheimer's Disease (CTAD) 2025 conference to argue that tau is still a viable target-if drug designers hit the right part of the protein-while investors and scientists pivot their attention to inflammation and vascular pathways.
Anti-tau Setbacks Raise the Bar for New Entrants
Tau-directed drugs have been among the most high-profile disappointments in Alzheimer's disease (AD) R&D. J&J's recent miss with posdinemab follows last year's Phase II failure of UCB's bepranemab and Eli Lilly's inability to replicate its amyloid success with the anti-tau candidate LY3372689. Collectively, these readouts have fed a narrative that tau may be an intractable or poorly understood target for disease modification.