Sanofi Acquires Vicebio for $1.15B to Strengthen Vaccine Portfolio

Sanofi has announced its acquisition of Vicebio Ltd, a privately held biotechnology company based in London, for an upfront payment of $1.15 billion, with additional milestone payments of up to $450 million tied to development and regulatory achievements. The strategic acquisition strengthens Sanofi's vaccine pipeline through Vicebio's proprietary 'Molecular Clamp' technology and adds an early-stage combination vaccine candidate targeting respiratory syncytial virus (RSV) and human metapneumovirus (hMPV).

The centerpiece of this acquisition is Vicebio's 'Molecular Clamp' technology, which represents an advancement in vaccine design by stabilizing viral proteins in their native shape. This stabilization enhances the immune system's ability to recognize and respond to these proteins more effectively. The technology enables the development of fully liquid combination vaccines that can be stored at standard refrigeration temperatures (2–8°C), eliminating the need for freezing or freeze-drying processes that complicate manufacturing and distribution.

This technological advantage extends to the delivery format, as fully liquid vaccines can be made available in prefilled syringes, improving ease of use, safety, and operational efficiency across healthcare settings. For Sanofi, which already maintains a presence in respiratory vaccines through its flu and RSV prevention products, this acquisition provides an opportunity to diversify its portfolio with a non-mRNA vaccine option, offering increased choice for physicians and patients.

"We are excited to join Sanofi. Their global scale and deep expertise in vaccine development provide the ideal environment to fully realize the potential of our innovative technology. As part of the Sanofi team, we look forward to advancing our platform and pipeline to deliver meaningful benefits for patients and public health," said Emmanuel Hanon, Chief Executive Officer at Vicebio.

The transaction is expected to close in the fourth quarter of 2025, pending customary closing conditions including regulatory approvals. Sanofi has indicated that the acquisition will not significantly impact its financial guidance for 2025, suggesting the company views this as a strategic investment in future growth rather than an immediate revenue driver.

The deal reflects the pharmaceutical industry's continued focus on respiratory vaccines and innovative delivery technologies that can simplify distribution and improve patient access to preventive care.

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