GSK’s Malaria Candidate Vaccine, Mosquirix Receives Positive Opinion from European Regulators for the Prevention of Malaria in Young Children in Sub-Saharan Africa

GSK has announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has adopted a positive scientific opinion for its malaria candidate vaccine Mosquirix, also known as RTS,S, in children aged 6 weeks to 17 months. Following this decision, the World Health Organization (WHO) will now formulate a policy recommendation on use of the vaccine in national immunisation programmes once approved by national regulatory authorities.

RTS,S, which was developed in partnership with the PATH Malaria Vaccine Initiative (MVI), is the first candidate vaccine for the prevention of malaria to reach this milestone. While other vaccines tackle viruses or bacteria, RTS,S has been designed to prevent malaria caused by the Plasmodium falciparum parasite, which is most prevalent in sub-Saharan Africa (SSA). 

The CHMP scientific opinion is a key step in the regulatory process toward making RTS,S available alongside existing tools currently recommended for malaria prevention. The positive opinion for young children was based on the review of data assessing the candidate vaccine’s safety, efficacy and quality. Clinical data submitted for CHMP assessment were mainly from a Phase III clinical trial programme involving more than 16,000 young children that was conducted by 13 African research centres in eight African countries (Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique, Nigeria, and Tanzania).

Data from this trial programme demonstrate that over the first 18 months following three doses of RTS,S, malaria cases were reduced by almost half in children aged 5–17 months at the time of first vaccination and by 27% in infants aged 6–12 weeks. At study end, four doses of RTS,S reduced malaria cases by 39% over four years of follow-up in children, and by 27% over three years of follow-up in infants.  In areas of the highest malaria burden, more than 6,000 clinical malaria cases were prevented over the study period for every 1,000 children vaccinated. The efficacy of RTS,S was evaluated in addition to existing malaria control measures, such as insecticide treated bed nets, which were used by approximately 80% of the children and infants in the trial.

Sir Andrew Witty, CEO of GSK said: “Today’s scientific opinion represents a further important step towards making available for young children the world's first malaria vaccine. While RTS,S on its own is not the complete answer to malaria, its use alongside those interventions currently available such as bed nets and insecticides, would provide a very meaningful contribution to controlling the impact of malaria on children in those African communities that need it the most. The work doesn’t stop here and GSK remains committed to investing in R&D for malaria vaccines and treatments to find more ways to tackle this devastating disease.”

Dr David C. Kaslow, Vice President of Product Development at PATH said: “Today marks a significant scientific milestone for the long-standing partnership to develop a vaccine, yet several more steps remain before a malaria vaccine might reach the young children in Africa who most need protection against this deadly human parasite. PATH will continue to work with GSK and other partners to ensure that the evidence is available, as soon as possible, to support informed decision-making on those remaining steps.”

GSK has committed to a not-for-profit price for RTS,S so that, if approved, the price of RTS,S would cover the cost of manufacturing the vaccine together with a small return of around 5% that will be reinvested in R&D for second-generation malaria vaccines, or vaccines against other neglected tropical diseases.