FDA Grants Fast Track to Biogen’s Tau-Targeting BIIB080 for Alzheimer Disease

Biogen announced on April 2, 2025, that the US Food and Drug Administration (FDA) has granted Fast Track designation to BIIB080, a tau-targeting investigational antisense oligonucleotide therapy, to treat Alzheimer Disease.1

“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 Priya Singhal, MD, MPH, head of development at Biogen, in a statement.

Currently, BIIB080 is being evaluated in the global phase 2 CELIA study for individuals with early-stage Alzheimer disease. Investigators hoped to assess the potential for tau-targeting BIIBO80 to slow the worsening of mild cognitive impairment or mild dementia due to Alzheimer Disease.2

This is the first program that BIIB080 was evaluated in Alzheimer disease. A previous phase 1b study on mild Alzheimer Disease showed dose-dependent reductions in soluble tau protein in cerebrospinal fluid (CSF), decreasing tau pathology in the brain as measured by positron emission tomography (PET). BIIB080 brought promising results in exploratory endpoints of cognition and activities of daily living (n = 46).2

“This is the first time we’ve seen both strong target engagement and favorable trends on clinical outcomes with a novel mechanism targeting tau,” Singhal said in a 2023 press release.2 “While these are preliminary findings, we are excited about these results and continue to enroll the Phase 2 CELIA study. We believe defeating Alzheimer’s disease will take different approaches, and we are committed to exploring the targeting of tau as a new generation of treatment.”

The phase 1b study randomized participants to either a placebo or 10 mg, 30 mg, or 60 mg BIIB080 every 4 weeks. Some participants were randomized to 115 mg BIIB080 every 12 weeks. In the long-term extension study, participants received 60 or 115 mg every 12 weeks.

This trial showed favorable trends on the global Clinical Dementia Rating Sum of Boxes, Mini-Mental State Exam cognitive scales, and Functional Activities Questionnaire at week 100 in the high-dose group (n = 16). The treatment was generally well-tolerated, with most adverse events mild or moderate in severity. The most common adverse events included headache, back pain, extreme pain, post-lumbar puncture syndrome, and procedural pain.

“Alzheimer’s is a complex and fatal disease that we believe will require multiple therapeutic approaches to address its diverse pathologies,” Singhal said. 1“BIIB080, an investigational antisense therapy, is a differentiated approach to targeting tau, with promising potential for patients. We are advancing this program with urgency on behalf of people living with Alzheimer’s and their families.”

References

1. Biogen’s Investigational Tau-Targeting Therapy BIIB080 Receives FDA Fast Track Designation for the Treatment of Alzheimer’s Disease. Globe Newswire. April 2, 2025. https://www.globenewswire.com/news-release/2025/04/02/3054142/0/en/Biogen-s-Investigational-Tau-Targeting-Therapy-BIIB080-Receives-FDA-Fast-Track-Designation-for-the-Treatment-of-Alzheimer-s-Disease.html. Accessed April 2, 2025.

2. New Data from Biogen’s Investigational Antisense Oligonucleotide (ASO) Targeting Tau Shows Promise for Potential New Generation of Treatments in Early Alzheimer’s Disease. Biogen. October 25, 2023. https://investors.biogen.com/news-releases/news-release-details/new-data-biogens-investigational-antisense-oligonucleotide-aso. Accessed April 2, 2025.