Sanofi Acquires Vigil Neuroscience To Expand Neurology Portfolio With Potential Alzheimer’s Disease Treatment

Sanofi has announced that it will acquire Vigil Neuroscience, Inc., a clinical-stage biotechnology company focused on developing treatments for neurodegenerative diseases such as Alzheimer’s. Vigil is a publicly traded company, and this acquisition supports Sanofi’s strategy to expand its neurology pipeline, one of its four key disease focus areas. Through this transaction, Sanofi will gain full rights to VG-3927, Vigil’s lead investigational drug, which is expected to enter Phase 2 clinical trials for Alzheimer’s disease.

VG-3927 is an oral small molecule that activates TREM2, a receptor involved in regulating the function of microglia—immune cells in the brain. In Alzheimer’s disease, microglial activity is often impaired, leading to the buildup of toxic debris, chronic inflammation, and damage to nerve cells. By activating TREM2, VG-3927 may help microglia better respond to injury, clean up harmful material, and support brain health, potentially slowing or preventing further neurodegeneration. This approach offers a new direction, especially considering the limitations of currently approved Alzheimer’s treatments, which cannot stop or reverse disease progression and are available only to select patient groups due to stringent eligibility criteria.

Sanofi had previously made a $40 million strategic investment in Vigil in June 2024. This investment gave Sanofi an exclusive right of first negotiation to license or acquire rights to VG-3927. The full acquisition of Vigil is a continuation of Sanofi’s forward-looking approach to strategic equity investments and reflects its commitment to addressing serious medical challenges with innovative solutions.

Under the terms of the agreement, Sanofi will acquire all outstanding common shares of Vigil for \$8 per share in cash, representing an equity value of approximately $470 million on a fully diluted basis. In addition, Vigil shareholders will receive a non-transferable contingent value right (CVR) for each share they hold. This CVR entitles them to an additional payment of $2 per share, which will be made only if VG-3927 achieves its first commercial sale.

Houman Ashrafian, MD, PhD

Head of Research and Development, Sanofi, stated, “This acquisition fully supports Sanofi’s strategic focus on neurology and on advancing science and leveraging our expertise in immunology to solve areas of critical unmet need. TREM2 represents a compelling target at the intersection of immune dysregulation and neurodegeneration, particularly in people living with Alzheimer’s because they face devastating cognitive decline with limited treatment options. Vigil’s expertise is complementary to our capabilities in neurology and reinforces our dedication to developing innovative medicines to improve people’s lives. Vigil’s team is a welcome addition, and we look forward to working with them and the patient community.”

Ivana Magovčević-Liebisch, PhD, JD

President & Chief Executive Officer, Vigil, said in a statement, “We are incredibly proud of the extraordinary and diverse team at Vigil and the progress we have made in developing innovative TREM2-based therapeutics. We look forward to joining forces with Sanofi's team to leverage Sanofi’s resources, broad platform and far-reaching network to fully unlock and accelerate the development of VG-3927 for the potential treatment of Alzheimer’s disease – a devastating disease with significant unmet need.”

The acquisition does not include VGL101, Vigil’s second drug program. As part of the deal, major Vigil stakeholders including Atlas Ventures, CEO Ivana Magovčević-Liebisch, and Bruce Booth have entered into voting agreements to support the transaction. Together, their holdings represent around 16.2% of Vigil’s outstanding shares. The completion of the acquisition is subject to customary closing conditions, including approval from a majority of Vigil’s shareholders, regulatory review under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, and other standard requirements. Both companies expect the deal to close in the third quarter of 2025. Sanofi has confirmed that the transaction will not affect its financial guidance for the year.