The acquisition, which will give Sanofi a combination vaccine for respiratory syncytial virus and human metapneumovirus, follows the pharma’s potential $1.4 billion COVID vaccine licensing deal with Novavax last year, plus a number of other big-ticket commitments outside of the vaccine space.
Sanofi is snapping up U.K.-based startup Vicebio in a deal worth up to $1.6 billion, marking the latest big-ticket purchase in the French pharma’s dealmaking frenzy this year. The centerpiece of the Vicebio acquisition is a combination vaccine for respiratory syncytial virus (RSV) and human metapneumovirus (hMPV).
“We view the acquisition as evidence of Sanofi’s enthusiasm for developing protein-based combination vaccines,” analysts at Leerink Partners told investors in a Tuesday morning note. The deal also falls in line with what the analysts see as the “accelerating large-cap biopharma M&A activity.”
The front-loaded agreement involves a $1.15 billion upfront payment from Sanofi and includes potential milestones of up to $450 million, contingent on hitting certain development and regulatory achievements, as per a news release on Tuesday. The companies expect to wrap up the transaction in the fourth quarter, pending certain closing conditions, including regulatory clearances.
The combo RSV-hMPV vaccine, called VXB-241, recently completed a Phase Ib study that tested four dose levels in more than 150 healthy volunteers. The study ended in February but the privately held biotech has yet to release findings from it.
According to Tuesday’s news release, VXB-241 “complements Sanofi’s position in the respiratory vaccines space.” The pharma owns the RSV immunizing antibody Beyfortus, which is approved for use in newborns and infants up to 24 months of age. Last year, Beyfortus made $1.77 billion. In May 2024, Sanofi bolstered its respiratory pipeline with Novavax’s protein-based COVID-19 vaccine, paying up to $1.4 billion in an exclusive licensing agreement.
Aside from VXB-241, Vicebio is advancing a combo RSV, hMPV and parainfluenza type 3 vaccine, which set to start Phase I testing in the third quarter. The biotech is also working on an avian flu vaccine, scheduled for Phase I development in the second quarter of 2026, and various COVID-19 vaccines.
Tuesday’s acquisition will also give Sanofi access to Vicebio’s Molecular Clamp platform, which stabilizes viruses in their natural shape, in turn allowing the body’s immune system to more effectively respond to them. The Molecular Clamp technology also makes possible liquid combination vaccines that are stable at standard refrigeration temperatures, leading to simpler manufacturing and aiding in distribution, as per Sanofi’s news release.
Vicebio is Sanofi’s latest purchase in what has been a buying spree this year. In March, the pharma bought Dren Bio’s bispecific antibody DR-0201, being developed for B cell non-Hodgkin lymphoma and autoimmune rheumatic diseases, for $600 million upfront. In May, Sanofi acquired Vigil Neuroscience and its Alzheimer’s disease therapy VG-3927 for $470 million upfront. A month later, the pharma put up to $9.5 billion on the line to buy Blueprint Medicines in what is one of the year’s largest acquisitions so far.
