Novartis AG developed a new class of experimental malaria drugs, its second in 14 months, advancing the search for treatments to replace current medicines as they lose potency against the infectious killer.
The drugs, called imidazolopiperazines, attack parasites that cause malaria earlier than currently approved therapies, according to a study published online by the journal Science today. That means they may be useful both for treating malaria and protecting against it.
Researchers are hunting for new treatments against malaria amid signs the disease is becoming resistant to drugs derived from artemisinin, the basis of the most-effective medicines, jeopardizing global efforts to curb the malady.
“If we lose the artemisinins, then we’re essentially naked again,” said Paul Herrling, head of corporate research at Basel, Switzerland-based Novartis. The new drugs work in a different way than existing medicines, meaning they’ll “probably be active on all resistant strains of malaria that we know, and even on potential resistant strains to artemisinins,” Herrling said in a telephone interview today.
Malaria kills a child in Africa every 45 seconds, according to the World Health Organization. It infects about 225 million people each year and causes more than 780,000 deaths, making it the world’s third-deadliest infectious disease behind AIDS and tuberculosis.
The malady is caused by a microscopic parasite called Plasmodium, which female mosquitoes can transmit in their saliva while biting. The parasites travel to the liver, where they multiply before spilling into the bloodstream, invading red cells and causing them to stick to the walls of capillaries, slowing blood flow. Without treatment, sufferers can die from organ failure.
While most current drugs clear the parasites from the blood, the bugs can lie dormant in the liver, causing recurrences months or years later.
The research, led by David Plouffe at a Novartis lab in San Diego and Stephan Meister at the Scripps Research Institute in La Jolla, California, found that one of the new drugs attacked the parasites both in the liver and in the blood when tested in mice.
Given to healthy mice, it also protected them against malaria by preventing the bugs from multiplying in the liver, suggesting that if the same results can be achieved in humans, the drug may one day be used by travelers in the same way as GlaxoSmithKline Plc’s Malarone.
Novartis plans to start testing the drug in humans early next year, Herrling said. The company has almost completed the first stage of trials for another new medicine discovered last year, he said.
The research was funded by the Wellcome Trust, the Medicines for Malaria Venture and Singapore’s Economic Development Board.