Anti-MTBR Tau Antibody Etalanetug Receives FDA Fast Track Designation
Wednesday, September 17, 2025
Eisai Co., Ltd. has announced that etalanetug (development code: E2814), an investigational anti-MTBR (microtubule binding region) tau antibody, has been granted Fast Track designation by the U.S. Food and Drug Administration (FDA). The designation is intended to speed up the development of therapies addressing serious conditions such as Alzheimer’s disease (AD), where there remains a significant unmet medical need.
Alzheimer’s disease is a progressive neurodegenerative condition marked by amyloid-beta plaques and tau protein tangles in the brain. Both are thought to play a role in the process of neurodegeneration. Etalanetug is designed to target specific MTBR-containing tau species, known as tau seeds, which drive the spread of tau pathology across brain regions. The antibody was discovered through a research collaboration between Eisai and University College London.
In a Phase I/II study (Study 103, NCT04971733) involving patients with Dominantly Inherited Alzheimer’s Disease (DIAD), etalanetug showed target engagement with MTBR-tau in cerebrospinal fluid. The trial also demonstrated a reduction in MTBR-tau243, a biomarker of tau pathology, and suggested a potential suppression of tau accumulation in the brain.
The antibody is now being studied alongside lecanemab, an anti-amyloid β protofibril antibody, in two trials: the Tau NexGen Phase II/III study (NCT05269394) for DIAD, led by the Dominantly Inherited Alzheimer Network Trials Unit at Washington University School of Medicine, and a Phase II trial (Study 202, NCT06602258) targeting sporadic early Alzheimer’s disease.
If therapies targeting tau become available following amyloid-focused approaches, they are expected to represent a major step forward in the treatment of Alzheimer’s disease. Eisai continues to prioritise neurology as a key area, with the aim of advancing treatments that improve outcomes for people living with dementia and related conditions.
Source: prnewswire.com
