Sanofi announced it has agreed to acquire Vigil Neuroscience, a clinical-stage biotech company focused on therapies for neurodegenerative diseases. The deal will strengthen Sanofi’s neurology pipeline through the addition of VG-3927, a promising oral TREM2 agonist being developed for Alzheimer disease (AD). Currently expected to enter Phase II trials, VG-3927 is designed to activate microglia, potentially introducing a novel mechanism to slow or prevent neurodegeneration.¹

How Does This Acquisition Fit Into Sanofi’s Broader Strategy in Neurology?

Under the terms of the agreement, Sanofi will acquire all outstanding shares of Vigil for approximately $470 million. In addition, Vigil shareholders will receive a non-transferable contingent value right per share, which entitles them to a future $2 cash payment upon the first commercial sale of VG-3927.¹

“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, MD, PhD, head, research, development, Sanofi, in a press release. “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 are a welcome addition, and we look forward to working with them and the patient community.”

Building on a Prior Strategic Investment

The acquisition builds on Sanofi’s $40 million strategic investment in Vigil made in June 2024. That investment granted Sanofi exclusive rights of first negotiation to license, acquire, or otherwise secure rights to develop, manufacture, and commercialize VG-3927.¹

This marks Sanofi’s second acquisition of the year. In March, the company announced a deal with Dren Bio to acquire DR-020, a CD20-directed bispecific antibody in early clinical trials for refractory B-cell-mediated autoimmune diseases. Sanofi paid $600 million upfront in that transaction, with Dren eligible for up to $1.3 billion in milestone payments.²

Vigil’s CEO Highlights Synergies with Sanofi’s Platform

“We are incredibly proud of the extraordinary and diverse team at Vigil and the progress we have made in developing innovative TREM2-based therapeutics,” said Ivana Magovčević-Liebisch, PhD, JD, president, CEO, Vigil Neuroscience, in the press release. “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.”

AD Remains a Pressing Unmet Need

According to Medical News Today, AD accounts for 60% to 80% of all dementia cases in the United States. Although most common in people over 65 years of age, the disease can also affect individuals in their 40s and 50s, and in rare cases, those in their 30s.³

Deal Structure and Closing Timeline

The transaction is expected to close in Q3 2025, pending shareholder and regulatory approvals. Notably, it excludes Vigil’s second program, VGL101, and is not expected to impact Sanofi’s financial guidance for 2025.¹

“Sanofi’s complementary capabilities and commitment to bring innovative therapies to patients align with our mission and what we have passionately been working toward over the past five years,” continued Magovčević-Liebisch, in the press release. “We want to thank Vigil’s exceptional employees for their unrelenting dedication and our patient communities for their steadfast engagement, to whom I extend my deepest gratitude. Together, we look forward to following Sanofi’s journey in advancing next-generation small molecule TREM2 therapies for severe neurodegenerative diseases and potentially offering new treatment options to patients.”⁴

References

1. Press Release: Sanofi to acquire Vigil Neuroscience, Inc., adding a new investigational medicine to treat Alzheimer’s disease to the neurology pipeline. Sanofi. May 21, 2025. Accessed May 22, 2025. https://www.sanofi.com/en/media-room/press-releases/2025/2025-05-21-23-15-31-3086232

2. Sanofi Bolsters Immunology Pipeline with Acquisition of Dren Bio’s DR-0201 for Up to $1.9 Billion. PharmExec. March 20, 2025. Accessed May 22, 2025. https://www.pharmexec.com/view/sanofi-bolsters-immunology-pipeline-acquisition-dren-bio-dr-0201-1-9-billion

3. What to know about Alzheimer’s disease. MedicalNewsToday. Accessed May 22, 2025. https://www.medicalnewstoday.com/articles/159442

4. Vigil Neuroscience Enters into Definitive Merger Agreement to be Acquired by Sanofi. GlobeNewswire. May 21, 2025. Accessed May 22, 2025. https://www.globenewswire.com/news-release/2025/05/21/3086234/0/en/Vigil-Neuroscience-Enters-into-Definitive-Merger-Agreement-to-be-Acquired-by-Sanofi.html