Sanofi has agreed to acquire Vicebio Ltd, a biotechnology company developing next-generation vaccines against respiratory viruses, in a deal valued at up to $1.6 billion. The acquisition grants Sanofi access to Vicebio’s proprietary Molecular Clamp technology, which enables the development of multivalent vaccines targeting multiple respiratory pathogens.

Under the terms of the agreement, Vicebio shareholders will receive an upfront payment of $1.15 billion and up to $450 million in development and regulatory milestone payments, subject to customary closing conditions.

Vicebio’s lead asset, VXB-241, is a bivalent vaccine in exploratory Phase 1 clinical trials targeting Respiratory Syncytial Virus (RSV) and Human Metapneumovirus (hMPV). Both viruses are major causes of severe respiratory disease, particularly in elderly populations and those with weakened immune systems. Interim data from the Phase 1 trial indicates a favourable safety and tolerability profile in adults aged 60 and above.

The Molecular Clamp technology, developed at The University of Queensland and licensed to Vicebio, stabilises viral glycoproteins to elicit strong immune responses and supports high-yield production of ready-to-use liquid multivalent vaccine formulations. It has broad applicability to a range of respiratory viruses, including RSV, hMPV, parainfluenza viruses, influenza, and coronaviruses.

Vicebio was established by Medicxi to advance novel vaccines against respiratory viral infections. The company completed a Series B financing round in September 2024 led by TCGX with participation from Goldman Sachs Alternatives, Avoro Ventures, venBio Partners, UniQuest, and Medicxi, supporting accelerated clinical development of VXB-241 and future candidates.

Dr Giovanni Mariggi, chairman of Vicebio and partner at Medicxi, said: “Our aim in creating Vicebio was to back a clear product vision to develop a best-in-class vaccine against respiratory viruses. We are extremely proud of what we have accomplished in the last few years thanks to a team effort by the Company, University of Queensland, our investors and the Board. We are excited to partner with Sanofi which will further accelerate VXB-241’s development to ensure it ultimately benefits those in need.”

Cariad Chester, managing partner at TCGX, added: “Vicebio has successfully developed best-in-class multivalent vaccines targeting leading causes of respiratory disease. These vaccines have the potential to protect millions of patients from life-threatening viral infections and we are thrilled to partner with Sanofi to accelerate their development. We look forward to working with Sanofi and combining our innovative technology with Sanofi’s global clinical development capability.”

Dr Emmanuel Hanon, chief executive officer of Vicebio, said: “Vicebio and its incredibly passionate team have been driven by the ambition to develop next-generation vaccines aimed at targeting multiple life-threatening respiratory viruses simultaneously. This acquisition validates our ability to combine innovation and deep scientific expertise towards a common goal of advancing public health prevention, and we’re excited to enter the next chapter to accelerate the global impact of our work.”

Goodwin Procter acted as legal counsel to Vicebio.