Merck & Co – known as MSD outside the US and Canada – has shared positive top-line results from a phase 2b/3 study of its investigational respiratory syncytial virus (RSV) preventative monoclonal antibody in infants.
RSV is a common respiratory virus characterised by several mild, cold-like symptoms. Although most people can recover within a week or two, it can cause severe illnesses such as bronchiolitis and pneumonia in certain groups, including young infants.
Approximately 30,000 hospitalisations in children aged under five years are caused by RSV every year in the UK.
Merck’s clesrovimab (MK-1654) is an investigational extended half-life monoclonal antibody developed as a passive immunisation to protect infants through their first RSV season.
The MK-1654-004 trial has been comparing a single dose of the candidate against placebo in healthy preterm and full-term infants.
The drug met its primary safety and efficacy endpoints, including reducing medically-attended lower respiratory infections caused by RSV through day 150.
Detailed results from the study will be presented at an upcoming scientific congress, Merck said, adding that it plans to file the findings with global regulatory authorities.
Dr Paula Annunziato, senior vice president, infectious diseases and vaccines, global clinical development, Merck Research Laboratories, said: “RSV is highly contagious and can cause inflammation in the airways of infants, leading to difficulty breathing… We are encouraged by these findings and look forward to working with regulators to provide a new option to help address the impact of RSV on infants and their families.”
The results come just one week after the UK government announced a national vaccination programme to protect infants through maternal immunisation and older adults against RSV.
The rollout, which will begin next month in Scotland and in September in England, Wales and Northern Ireland, will make the UK the first country worldwide to have a national programme that uses the same vaccine, Pfizer’s Abrysvo, to protect both age populations against the virus.
The new initiative will include a vaccine for pregnant women over 28 weeks to help protect their babies, a routine programme for those aged over 75 years and a one-off campaign for people aged 75 to 79 years.