Investigational Tau-Targeting Therapy for Alzheimer Disease Receives FDA Fast Track Designation

The Food and Drug Administration (FDA) has granted Fast Track Designation to BIIB080 (Biogen, Cambridge, MA), an investigational antisense oligonucleotide (ASO) therapy that targets tau, for the treatment of Alzheimer disease (AD). According to Biogen, BIIB080 is the first tau-targeting ASO to enter clinical development for AD and functions by targeting microtubule-associated protein tau (MAPT) mRNA, reducing tau protein production.

The FDA's decision followed data from a phase 1b study (NCT03186989) involving 46 participants with mild dementia due to AD who were randomized to placebo or BIIB080 in 1 of 4 dose cohorts (10 mg, 30 mg, or 60 mg every 4 weeks [Q4W] or 115 mg Q12W). In a long-term extension study (LTE), all participants received 60 mg or 115 mg Q12W.

• BIIB080 demonstrated dose-dependent reductions in soluble tau protein in cerebrospinal fluid (CSF) and decreased aggregated tau pathology in the brain as measured by positron emission tomography (PET).
• CSF tau levels were reduced by approximately 60% from baseline for all dose groups by the end of the LTE.
• Favorable trends were also observed across multiple exploratory measures of cognition and function in the LTE, including the Clinical Dementia Rating Sum of Boxes (CDR-SB), Mini-Mental State Exam (MMSE), and Functional Activities Questionnaire (FAQ) at week 100.

"We are encouraged by the FDA's Fast Track designation for BIIB080, which highlights the urgent need for innovative treatments targeting tau pathology in Alzheimer's disease," said Dr. Priya Singhal, Head of Development at Biogen. “Alzheimer’s is a complex and fatal disease that we believe will require multiple therapeutic approaches to address its diverse pathologies.”

The phase 2 CELIA study (NCT05399888) evaluating BIIB080 in individuals with early-stage AD is now fully enrolled, with data expected in 2026.

Source: Biogen’s investigational tau-targeting therapy BIIB080 receives FDA fast track designation for the treatment of Alzheimer’s disease. Press release. Biogen. April 2, 2025. https://investors.biogen.com/news-releases/news-release-details/biogens-investigational-tau-targeting-therapy-biib080-receives