New Malaria Drug Could Save Tens of Thousands

ATLANTA—It's not often that spontaneous applause erupts halfway through a scientific talk. But when malaria researcher Arjen Dondorp came to the crucial slide of his presentation here on Saturday, the audience at the American Society of Tropical Medicine and Hygiene's annual meeting couldn't contain itself. Dondorp's study showed that compared with an older drug called quinine, a new one called artesunate reduces the risk of death from severe malaria in African children by 23%—a finding that could save tens or even hundreds of thousands of lives annually.

The findings, which are published online today in The Lancet, "are very clear," says Melba Gomes, a scientist working on antimalarial policy at the World Health Organization (WHO) in Geneva, Switzerland. Given the results of this and previous studies, artesunate should replace quinine as soon as possible worldwide, she says.

Malaria kills up to a million people a year. Most are African children. In its early stages, the disease can be treated with pills, but in severe cases, when time is of the essence, drugs need to be given intravenously or via an intramuscular injection. The most widely used drug for this purpose until now was the centuries-old quinine, derived from the bark of a South American tree; no modern drug had worked better.

But in 2005, a large study in four Asian countries, led by Dondorp and Nicholas White, both employed by the University of Oxford in the United Kingdom but based at Mahidol University in Bangkok, showed that injections of artesunate reduced deaths from severe malaria by 35% over quinine. (Artesunate is part of a drug family derived from Artemisia annua, a plant that has long been used in Chinese medicine.) Since then, several Asian countries have started replacing quinine with artesunate for severe malaria. But it was unclear if the results would translate to Africa, where the population has a different genetic makeup and is generally more likely to be exposed to malaria. Moreover, only 202 of the 1603 subjects in the Asian study were children—not enough, most scientists felt, to warrant a major shift in drug policy.

For the new trial, Dondorp and White gathered a group of collaborators at 11 research centers in nine African countries. Together, they enrolled 5425 children under 15 years of age who had severe malaria. Of the children who received quinine, 10.9% died; in the artesunate group, 8.5% died. The difference may sound marginal, but it's a 22.5% reduction in mortality--reason to be "euphoric," says Dondorp. If all African children with severe malaria received artesunate in time, between 100,000 and 200,000 lives could be saved annually, he says.

The difference between the drugs might be that, as opposed to quinine, artesunate also kills very young malaria parasites, Dondorp says. As a result, fewer infected red blood cells might clog up the tiny blood vessels in patients' organs.

Artesunate, produced by a Chinese company called Guilin Pharmaceutical, is easier to give than quinine, which must be administered very slowly and carefully to avoid a dangerous drop in blood pressure. Artesunate is slightly more expensive, but its administration is cheaper, and an as-yet-unpublished cost-effectiveness study by Dondorp and colleagues shows that the average cost per life saved using the new drug is only $123. That's very low compared with many other interventions.

Changing national drug policies can take many years, however. As soon as possible, WHO should recommend artesunate for severely ill children, because that will stimulate African countries to switch policies, says Olugbenga Mokuolu, a clinical researcher at the University of Ilorin Teaching Hospital in Nigeria who collaborated on the study. Abul Faiz of the Sir Salimullah Medical College in Dhaka, who sits on the panel that makes WHO's malaria treatment recommendations, says the group will likely meet soon to discuss the new findings.