New Delhi: An international team of scientists has reported a new class of drug candidates which, if successful in clinical trials, could potentially replace the current range of anti-malarial drugs and offset worries over increasing reports of resistance to artemisinin, the main ingredient in the fight against the disease.
Preliminary clinical trials are expected to begin later this year, researchers from the Singapore-based Novartis Institute for Tropical Diseases, who were among the key researchers, said in a press statement.
In a report to be published in Friday’s edition of the journal Science, the researchers say the drug was promising because NITD609, as the compound is now called, killed two species of parasites—plasmodium falciparum and plasmodium vivax—in their initial stages of development. The chemical was also effective against drug-resistant strains, safe for a large number of human cells, and could be administered as a single dose.
“We’re very excited by the new compound,” Elizabeth Winzeler, a Scripps Research associate professor and member of the Genomics Institute of the Novartis Research Foundation, said. “It has a lot of encouraging features as a drug candidate, including an attractive safety profile and potential treatment in a single oral dose.”
Medicinal chemists say NITD609, one of a new class of chemicals called spiroindolones, could be formulated as a tablet and made 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 anti-malarials,” Winzeler said. “The ideal new malaria drug would not just be a modification of existing drugs, but would have entirely novel features and mechanism of action. NITD609 does.”
Since 2009, concerns have surfaced over resistance to artemisinin, only available from herbs in China. Artemisinin has been in wide use as an anti-malarial for over a decade and replaced quinine, a class of compounds that has been used to treat malaria for nearly a century.
Last year, the World Health Organization said the “emergence of (malarial) parasites resistant to artemisinin at the Thai- Cambodia border may seriously undermine the success of the global malaria control efforts”.
Since 2007, India officially counts over a million cases of malaria annually, with at least 1,000 dying from the disease, says the government’s National Vector Borne Disease Control Programme.
Globally, malaria poses a risk to half the world’s population and more than one million people die of the disease each year. The malaria map has been reduced considerably over the past 50 years, but the disease has defied elimination in areas of intense transmission.
Indian experts suggest that it’s too early to be excited about the work, but add that the threat of drug resistance to artemisinin is extremely serious.
“Not more than four to five suitable drug candidates are available for malarial drugs and many promising compounds fail,” said Chetan Chitnis, who works on malarial vaccines at the International Centre for Genetic Engineering and Biotechnology, New Delhi. “But if this work is published in Science today it will take at least 10-15 years for a drug to materialize, by which time artemisinin resistance would have spread beyond Cambodia. I haven’t seen the data, but any promising drug candidate is always welcome.”