Two-in-one antimalarial 'could reactivate older drugs'
Scientists have created a potent antimalarial drug that can also resurrect the activity of defunct antimalarials.
The 'dual-function' drug blocks a process essential to the malaria parasite's survival. In addition, it can both reverse resistance to older antimalarial drugs (when used in combination), and maintain the activity of newer drugs.
The scientists, led by Jane Kelly of the US-based Portland Veteran Affairs Medical Center, created the drug by combining two desirable traits into one molecule. Their work was published in Nature last week (8 April).
They found the drug was active against Plasmodium falciparum in both 'test-tube' studies and infected lab mice. More importantly, when used in combination with quinoline antimalarials — the family that older antimalarials quinine and chloroquine belong to — the drug was active against both sensitive and resistant parasites.
And the new drug is unlikely to develop resistance itself because it targets a biological process rather than just the parasite. It is "difficult to imagine any simple set of mutational events that could bring about resistance", says Kelly.
"Modern antimalarial chemotherapy heavily relies on artemisinin-based treatment. Given the lack of alternative therapeutics there is a pressing need for a new chemical entity and a novel strategy for drug combinations to combat multi-drug resistance," she adds.
Kelly told SciDev.Net that the team's 2-in-1 drug, "not only adds a new [type of drug] to the list of antimalarials, but also provides a uniquely powerful therapeutic tool to enhance the efficacy of newer drugs (e.g. piperaquine) and to restore the efficacy of older drugs (e.g. quinine and chloroquine)".
The drug is safe in mice and should be fairly inexpensive to make. Older quinolines — which the drug would most likely be used alongside — are also very cheap.
But Kelly admits that the drug is far from ready to use in humans. Her team is still improving the antimalarial function of the drug and testing it in mice.
Nature (2009) doi 10.1038