GlaxoSmithKline’s investigational malaria vaccine RTS,S/AS02 has shown its ability to safely induce significant protection against malaria infection in infants aged 10-18 weeks.

Results of a Phase II trial of the vaccine, undertaken in 214 infants in Mozambique and published online in The Lancet, showed that RTS,S’ efficacy against new infections with the disease was 65% over a three-month follow-up period, and also that is reduced episodes of clinical malaria by 35% over six-months.

According to GSK, this level of efficacy is in line with the estimated 45% cut in new infections observed in a trial of children aged one-four in Mozambique back in 2004.

The trial also met its actual primary endpoint of safety, finding RTS,S to be safe and well-tolerated in this age group, with a reactogenicity profile similar to that of other standard vaccines in the Expanded Programme on Immunization.

Explaining the importance of the study’s findings, Pedro Alonso, from the Manhica Health Research Centre in Mozambique, author of The Lancet article and lead investigator of the trial, said: “We have shown for the first time that a vaccine can reduce the risk of malaria infection in young African infants…These tantalising and unprecedented results further strengthen the vision that a vaccine may contribute to the reduction of the intolerable burden of disease and death caused by malaria.”

Paving the way for filing

And Christian Loucq, director of the PATH Malaria Vaccine Initiative, a key partner in the development of GSK’s vaccines, added: “While other Phase II studies of this vaccine candidate are underway, this study helps pave the way for a pivotal Phase III trial of what could be the first malaria vaccine for infants and young children in Africa.”

If the vaccine continues to show promise, it will move into a Phase III clinical programme in the second half of 2008, and if this is successful, a submission to regulatory authorities will follow in 2011, GSK said.