Shelving malaria

Roger Bate | 02 Apr 2009
Foreign Policy
We have all heard the stats and the supposed fixes for malaria: The mosquito-borne illness claims the lives of roughly a million people each year. Ninety percent of the deaths will be in Africa, mostly among pregnant women and children. Thanks to poor medical care and uneven prevention, 10 malaria victims will die before you finish reading this column.

Bed nets and insecticide can help prevent mosquito-borne transmission. And for years, medical researchers have searched for other ways to limit malaria's damage. But one of the easiest fixes might come not from new drugs, but from extending the shelf life of existing treatments. If international drug regulators heed the results of a new study, which I conducted with several colleagues, some of the most promising malaria remedies can stay on apothecary shelves for months or years longer.

To date, there are no promising vaccines for malaria. The disease is treatable, but over the past 30 years malaria has shown an alarming resistance to traditional treatments such as chloroquine. Just one drug cocktail has so far evaded the same fate: a combination of traditional medicines and an ancient Chinese herbal remedy. Whereas today 60 to 70 percent of all treatments fail because of drug resistance or prescription or patient error, the success rate of this treatment, artemether-lumefantrine (ART-LUM), is higher than 96 percent after just three days.

Right now, the International Conference on Harmonization, a malaria treatment framework used by the World Health Organization, stipulates a shelf life of 24 months for ART-LUM. This is problematic, because it takes 14 months to grow ingredients and manufacture the drug, and purchasers typically demand 18 months of remaining shelf life once they receive the medication. There is hardly any time left on the clock when drugs get into patients' hands.

A short shelf life makes matters even more troublesome in the developing world, where malaria is most prevalent and where a limited healthcare infrastructure makes it difficult to predict just how many pills will be needed, and when. Procuring, distributing, and administering medicines is costly and complex. Facing uncertain demand, purchasers often under-order to avoid a costly overstock that then expires before purchase. The implications are obvious if an outbreak strikes.

Extending the shelf life of ART-LUM would make it easier and cheaper to acquire and keep stocks of the drug in the world's most endemic areas. And according to our research, no further work needs to be done in the lab; ART-LUM might already be potent well after its stated two-year shelf life.

Our study tested 70 samples of ART-LUM from malaria researchers' private supplies and private pharmacies and kiosks in major cities across Africa -- in Kenya, Mozambique, Nigeria, Rwanda, Tanzania, Uganda, and Zambia. Most of these medicines had not been stored in ideal, environmentally controlled conditions; they were kept under field conditions. Malaria is fought in the real world -- not in a climate-controlled laboratory.

The samples were between eight and 65 months past their expiration dates, but just two batches failed basic potency testing. One of the failures was 14 months past its expiration date; the other was our oldest sample, at 65 months past. The packaging on both of these failing samples showed visible damage, which could have been sufficient to spoil the integrity of the tablets. Ninety-seven percent of the expired ART-LUM was still potent, with many samples more than a year past their throwaway date.

Our research is in no way conclusive, but it is important. Although our samples represented only one ten-thousandth of the ART-LUM produced last year, our study was broad and realistic. The overwhelming results indicate that international regulatory bodies should consider further laboratory and field testing of ART-LUM, especially analyzing the degradation byproducts. If the drug's life can be extended, the lives of thousands more people will be longer as well.