First artemisinin based malaria drug may meet resistance, expert says

This year, the U.S. Food and Drug Administration is expected to approve the first malaria drug to contain artemisinin, a wormwood derivative from China that has proven effective for malaria in Africa and Asia.

Although there are only about 1,500 reported cases of malaria treated in this country each year, this approval would also make the drug available to the military and to Americans planning to go abroad. However, worldwide malaria is still one of the most serious infectious diseases, affecting 2 to 3 billion people, with up to two million deaths annually.

The drug, named Coartem, is made by the Swiss company Novartis. It combines artemether, an artemesinin derivative, with lumefantrine, a drug developed by Chinese scientists, which does not kill parasites as quickly but lingers in the blood a while longer. By mopping up parasites that artemisinin misses, lumefantrine helps prevent resistance that would defeat the drug, as has occurred with other therapies like chloroquine.

According to University of Pennsylvania pharmacologist Doron Greenbaum, Ph.D., although the exact mechanism by which artemisinin kills parasites is still open to considerable debate, the drug likely acts against one or more protein targets that may make it susceptible to resistance that has developed to most other drugs. Drug resistance to artemisinin has already been shown to occur in the laboratory, and reports have already surfaced about potential resistance in malaria endemic regions like southeast Asia. Thus the potential success of Coartem treatment for malaria should be greeted with cautious optimism knowing that resistance is likely to arise and that other new drugs will need to be developed quickly.