GSK starts phase 3 study of RSV maternal candidate vaccine

On Nov 24, 2020

GlaxoSmithKline plc announced that patient dosing has begun in a phase 3 clinical programme investigating the safety and efficacy of its Respiratory Syncytial Virus (RSV) candidate vaccine for maternal immunisation (GSK3888550A), following presentation of positive phase 1/2 safety, reactogenicity and immunogenicity data last month

It is estimated that every year, 33 million cases of RSV occur in children less than 5 years of age globally, with more than 1.4 million hospitalisations of infants under 6 months of age^[1]. RSV is a leading cause of respiratory infections such as bronchiolitis (inflammation and congestion of the small airways or bronchioles of the lung) and viral pneumonia (an inflammatory condition of the lung small air sacs or alveoli) in infants.

Emmanuel Hanon, Senior Vice President and Head of Vaccines R&D for GSK, said: “RSV burden is high amongst young infants – a vaccine which protects them from birth would represent significant progress in addressing the burden of RSV, preventing infant illness and families’ distress, as well as reducing the associated burden for society. Advancing our portfolio of RSV vaccine candidates based on robust available data is a major step towards GSK’s goal of reducing the RSV-associated disease burden around the world.”

The candidate vaccine contains a recombinant subunit pre-fusion RSV antigen (RSVPreF3) which has shown promising safety and immunogenicity in a phase 1/2 study in non-pregnant women, as presented at the ID Week Congress in October 2020. The data showed the candidate vaccine was well-tolerated and able to rapidly boost the pre-existing immunity in non-pregnant women leading to a high level of protecting neutralising antibodies, with a 14-fold increase in RSV-A and RSV-B neutralising antibody titers observed as early as one week after immunisation. First data in pregnant women are expected to be presented in 2021.

This candidate vaccine is part of a portfolio of RSV vaccine candidates that GSK is developing, which also includes candidates for infants and older adults. The candidate vaccines are based on different novel technologies, tailored to the needs of the populations most impacted. All three candidate vaccines have received FDA fast-track designation. The phase 3 programme for the older adult’s RSV candidate vaccine is on-track to start in the coming months, while the phase 1/2 (in RSV sero-naive infants) study with the paediatric RSV candidate vaccine is ongoing.