Multiple therapies deter the emergence of drug-resistance in malaria

New Study: Using multiple therapies deters the emergence of drug resistance in malaria

A new RFF study, published by the Proceedings of the National Academy of Sciences, offers hope that new types of treatment therapy can extend the effectiveness of anti-malarial drugs, benefiting victims of a disease that devastates countries around the world.

 FOR IMMEDIATE RELASE: September 4, 2008

CONTACTS: Stan Wellborn, RFF Director of Public Affairs, 202-328-5026

WASHINGTON – In a newly published study, researchers at Resources for the Future find that employing multiple first-line therapies against malaria leads to markedly improved outcomes for malaria victims over standard existing practice of providing the same antimalarial to all patients.

The findings add new evidence to support changes to current approaches used by public health practitioners in Asia, sub-Saharan Africa, and other malaria-prone regions of the world.

Using a model to review alternative therapeutic approaches over 20 years, the project by RFF researchers Maciej F. Boni, David L. Smith, and Ramanan Laxminarayan demonstrated that utilizing drug policies in which several therapies are made available to health-care systems delays the onset of severe drug resistance and reduces the chances that a patient receives an unsuccessful treatment.

Published online the week of September 2 by the Proceedings of the National Academy of Sciences, and entitled “Benefits of Using Multiple First-line Therapies against Malaria,” the report noted that the standard malaria treatment strategy recommends a single drug for the entire affected population, then employs a “wait-and-switch” strategy in which alternative medicines are administered when the initial one begins to fail. That approach often builds high resistance levels in the malaria parasite and increases the chance of treatment failures.

In the past century, chloroquine and sulfadoxine-pyrimethamine were widely used to combat malaria but the parasites eventually developed resistance. However, the malaria parasite does not yet appear to have become resistant to the newer artemisinin drugs. Today, multiple first-line therapies are not widely implemented due to operational challenges and expense, but the study offers compelling evidence for global leaders to work collaboratively to extend the longevity of artemisinin-based malaria drugs combined with partner drugs.

“Artemisinin-based combinations represent our best treatment option for malaria not just now but for the foreseeable future. Novel treatment strategies improve our ability to delay the emergence of resistance without the need to deny treatment,” said Laxminarayan.

In addition to the improved health outcomes, the report suggests, multiple first-line treatments may enjoy some operational advantages because they do not incur the economic costs involved in switching therapies and maintaining a high level of surveillance over patient progress.

“This is not to say that implementing multiple first-line therapies solves all of our malaria problems,” said Boni. “Antimalarial drug development needs to continue so that we have novel and highly effective antimalarials that can be plugged into the recommended strategies for combining multiple drugs.”

Maciej Boni currently is a Fellow at Oxford’s Centre for Genomics and Global Health and working at a clinical research unit in Vietnam. David Smith is associate director of disease ecology at the University of Florida Emerging Pathogens Institute. Ramanan Laxminarayan is a Senior Fellow at RFF.

The study was supported by a grant from the Bill and Melinda Gates Foundation.

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