Sanofi Tightens Grip on RSV with $1.15B Upfront Acquisition of Vicebio, Diversifying Beyond mRNA Vaccines
Sanofi has agreed to acquire UK-based Vicebio for up to $1.6 billion, with an upfront payment of $1.15 billion and up to $450 million in milestone payments135.
The acquisition provides Sanofi with an early-stage combination vaccine candidate, VXB-241, targeting both respiratory syncytial virus (RSV) and human metapneumovirus (hMPV); VXB-241 is currently in Phase 1 clinical trials3.
Vicebio's proprietary Molecular Clamp technology stabilizes viral proteins in their native shape, enabling more effective vaccine responses and allowing for liquid vaccines that can be stored at standard refrigeration temperatures (2–8°C)24.
This move diversifies Sanofi's vaccine pipeline beyond mRNA technology, strengthening its position in the respiratory vaccine space by adding a non-mRNA option21.
The acquisition complements Sanofi’s previous investments in vaccines and broadens its research and manufacturing capabilities in innovative vaccine platforms12.
Pending regulatory approval, the transaction is expected to close in the fourth quarter of 20251.
Sources:
1. https://www.biospace.com/business/sanofi-makes-1-6b-vaccine-bet-with-vicebio-acquisition
2. https://www.globenewswire.com/news-release/2025/07/22/3119150/0/en/Press-Release-Sanofi-to-acquire-Vicebio-expanding-respiratory-vaccines-pipeline.html
3. https://www.statnews.com/2025/07/22/sanofi-vaccine-vicebio-rsv-hmpv-acquisition/
4. https://vicebio.com/sanofi-to-acquire-next-generation-vaccine-biotech-vicebio-for-us1-6-billion/
5. https://www.ddw-online.com/sanofi-acquires-vaccine-biotech-vicebio-for-1-6-billion-35745-202507/