AstraZeneca and Sanofi have reported positive data reinforcing the consistency of their jointly developed monoclonal antibody, Beyfortus (nirsevimab), in protecting infants against respiratory syncytial virus (RSV) lower respiratory tract infections (LRTIs).
Among the key data presented at this year’s Respiratory Syncytial Virus Foundation (ReSViNET) Conference in Lisbon is the safety and efficacy findings from the full cohort of the phase 3 MELODY clinical trial.
The trial, which evaluated Beyfortus in healthy late pre-term and term infants entering their first RSV season, demonstrated an efficacy of around 70-80% against medically attended RSV LRTIs, including hospitalisations, versus placebo.
RSV is a contagious virus and the most common cause of LRTIs, including bronchiolitis and pneumonia, in infants. Although most people recover within a week or two, the virus can potentially cause severe illness in young infants, older adults and individuals with certain chronic medical conditions.
There were around 33 million cases of acute LRTIs leading to more than three million hospitalisations globally in 2019, and it was estimated that there were 26,300 in-hospital deaths of children aged under five years.
Beyfortus has been developed to offer newborns and infants direct RSV protection via an antibody to help prevent medically attended LRTIs caused by RSV and, because it confers the antibodies to the infant, it can offer protection for a broad infant population no matter what time of year a child is born.
“As RSV prevention continues to be an unmet public health need in infants, we are pleased to see potential solutions being brought forward to address the significant burden this highly contagious virus places on families and healthcare systems,” a Sanofi spokesperson told PMLiVE.
Beyfortus has already been approved in the EU and UK as the first and only approved RSV prevention designed for use in all infants.
The companies’ application is also currently under review by the US Food and Drug Administration, with a Prescription Drug User Fee Act expected in the third quarter of this year.
Iskra Reic, executive vice president, vaccines and immune therapies, AstraZeneca, said: “I am proud of AstraZeneca’s commitment to RSV and our continued focus on innovating antibodies to provide protection to the most vulnerable.
“We believe that Beyfortus has the potential to transform the medical community’s approach to preventing RSV infections in infants, and this is of particular importance given the recent surges of the virus amongst infants this past winter season.”