Vigil Neuroscience to be Acquired by Sanofi

Watertown-based Vigil Neuroscience has agreed to be acquired by drug giant Sanofi in a deal worth approximately $600 million. The transaction is expected to close in the third quarter of 2025. Vigil is a clinical-stage biotech focused on developing treatments for neurodegenerative diseases using microglia, the sentinel immune cells of the brain.

Iluzanebart, Vigil’s lead clinical candidate, is a fully human monoclonal antibody agonist targeting myeloid cells 2 (TREM2) in people with a rare and fatal neurodegenerative disease. Vigil is also developing VG-3927, a novel small molecule TREM2 agonist, to treat common neurodegenerative diseases associated with microglial dysfunction, with an initial focus on Alzheimer’s disease.

Activating TREM2 is expected to enhance the neuroprotective function of microglia in Alzheimer’s disease. In neurodegenerative diseases such as Alzheimer’s, microglial activation is poorly regulated, leading to debris accumulation, chronic inflammation and neurodegeneration in the central nervous system. Activation of TREM2 has shown to improve the activity of microglial cells. This helps prevent the neural degeneration frequently associated with adult-onset neurodegenerative diseases.

“This acquisition is fully supporting Sanofi’s strategic focus on neurology and on advancing science and leveraging our expertise in immunology to solve areas of critical unmet need,” said Houman Ashrafian, Head of R&D at Sanofi. “TREM2 represents a compelling target at the intersection of immune dysregulation and neurodegeneration, particularly in people living with Alzheimer’s…Vigil’s expertise is complementary to our capabilities in neurology and reinforces our dedication to developing innovative medicines to improve people’s lives.” (Source: Vigil Neuroscience Website, 21 May, 2025)