With the parasite responsible for most malaria cases -- Plasmodium falciparum -- developing resistance to widely-used treatments, researchers have developed a new drug to fight the mosquito-born disease.

Results of a clinical trial published in the journal Lancet Infectious Diseases have shown the drug to be effective against non-severe cases of malaria. The drug, called AQ-13, was able to clear the parasite responsible for the disease within a week, matching the effectiveness of the most widely-used treatment regimen, the study said. "The clinical trial results are extraordinarily encouraging," said the study's senior author Donald Krogstad, Professor at Tulane University in New Orleans, Louisiana. "Compared to the current first-line recommendation for treatment of malaria, the new drug comes out very well," Krogstad said. Mosquitoes infected by a parasite spread malaria, causing more than 200 million illnesses across the globe and more than 400,000 deaths annually. 

For decades, chloroquine was used to treat malaria, until Plasmodium falciparum developed resistance to it. Now, a drug combination -- artemether and lumefantrine -- is the primary treatment for malaria, although resistance is also developing to the drug combination in some countries.The researchers recruited 66 adult men in Mali with uncomplicated malaria, which is defined as malaria that is not life-threatening. Half were treated with AQ-13 and the other half received artemether and lumefantrine. Both drug groups had similar cure rates, the study said.

The researchers hope to expand testing of the drug to more participants, including women and children, before it can be widely recommended as a new treatment. The same biotechnology that helped the team develop the new drug has also identified similar drugs that also hold promise against drug-resistant parasites, Krogstad said. "The potential long-term implications are bigger than one drug," he said. "The conceptual step here is that if you understand the resistance well enough, you may be actually be able to develop others as well. We synthesised over 200 analogues and, of those, 66 worked against the resistant parasites," Krogstad said.