An experimental Novartis drug can clear malaria infection in mice with a single dose and scientists say it shows promise as a possible future treatment for one of the world's major killer diseases.
In a study published in the journal Science on Thursday, an international team of scientists said the drug, called NITD609, is effective against the two most common parasites responsible for malaria — Plasmodium falciparum and P. vivax — and also against a range of drug-resistant strains.
In experiments on mice with malaria, the scientists found that NITD609 works in a different way from other antimalarial drugs and that one oral dose was enough to clear the disease.
More safety tests are needed before the drug can be given to humans, but the researchers said that if those are positive, clinical trials in humans could begin at the end of this year.
"A single-dose cure would go a long way to addressing the unmet medical need in malaria, and we look forward to seeing how this compound performs in clinical trials," said Rick Davis, of Britain's Wellcome Trust, which supported the research.
The World Health Organization (WHO) says there are about 243 million cases of malaria each year, causing an estimated 863,000 deaths, mostly among young children in Africa.
Although malaria is preventable and curable, it is estimated that in Africa a child dies from the disease every 45 seconds.
The best treatments for malaria are artemisinin combination therapy (ACT) drugs made by firms like France's Sanofi-Aventis, but they can be expensive. Resistance to chloroquine and sulfadoxine-pyrimethamine, the cheapest malaria drugs, is becoming more common.
The experimental drug NITD609 belongs to a new class of drugs called spiroindolenes. It was identified by the Novartis Institute for Tropical Diseases (NITD) working in an international collaboration supported by the Wellcome Trust, the international Medicines for Malaria Venture (MMV), the U.S. National Institutes of Health (NIH) and several other bodies.
Scientists screened 12,000 chemicals using an ultra-high throughput robotic screening technique before they singled out NITD609 as a potential drug candidate.
Anthony Fauci, director of the NIH's National Institute of Allergy and Infectious Diseases, said the experimental compound had several "desirable features," including that it targets a parasite protein not attacked by any existing malaria drugs.
NITD609 also has properties which could enable it to be manufactured in pill form and in large quantities.
"From the beginning, NITD609 stood out because it looked different, in terms of its structure and chemistry, from all other currently used antimalarials," said Elizabeth Winzeler, also with the NIH, who worked on the team.
If NITD609 behaves similarly in people to the way it works in mice, she said in a report on the work, it may be possible to develop it into a drug that could be taken just once — far easier than current standard treatments in which malaria drugs are taken between one and four times a day for up to seven days.
British drugmaker GlaxoSmithKline is carrying out late-stage testing in people of an experimental vaccine against malaria and expects to see results by 2011. The firm says that if it proves effective, it will seek regulatory approval for the vaccine, called Mosquirix, by 2012.