Nick White: Artemisinin therapy for malaria
Malaria is the most important parasitic disease of man. Although most of the deaths occur in Africa, drug resistance has emerged from South-East Asia. Artemisinins, which are plant-derived compounds originally from the Chinese Materia Medica, are still today the best treatment for malaria, however, other drugs are also showing promising results. Clinical trials are also undertaken to find out the correct doses. All these developments contribute to our progress in getting malaria under control.
Q: What challenges does malaria pose in rural South-East Asia?
NW: Malaria is the most important parasitic disease of man and most of the deaths – we estimate that there are some two thousand deaths every day from malaria – occur in Africa, and they occur in children. But the parasites, which carry drug resistance genes which defeat the antimalarial drugs we have, have historically emerged from South-East Asia – not once, not twice, but now three times. So South-East Asia is where the resistance problems, that undermine our global malaria control efforts, come from. So South-East Asia is very important, although it doesn’t have such a large burden of disease.
Q: Is artemisinin therapy the way forward?
NW: Artemisinin therapy is definitely the way forward. Artemisinins, which are plant derived compounds originally from the Chinese Materia Medica, turned out to be the most highly effective drugs for the treatment of malaria – they’re the best drugs we’ve ever had. And after quite a lot of research and quite some political wrangling in the mid-2000s they have now become established as the treatment of choice for malaria, throughout the world. For uncomplicated falciparum malaria, and increasingly for the other malarias, artemisinin combination treatments are the first-line treatment. So we use a combination of artemisinins and another drugs – the same strategy underlines the treatment of tuberculosis, HIV and many cancers – combining drugs together to try and slow the emergence of resistance. And then in severe malaria we’ve shown in the largest ever trials conducted both in Asia and in Africa that artesunate, which is one of the artemisinin derivatives, is simply the best treatment for severe malaria, substantially reducing mortality, by up to a third. So they are, in short, by far the best drugs for the treatment of malaria.
Q: What about the prospect for the development of other drugs?
NW: The prospects for new drugs are better than they have been for the past three decades. It’s been quite difficult to produce new anti-infective drugs at all, and we’ve not been very productive in the last few decades for malaria. But in just the last five years some really promising compounds have entered early clinical development. It’s still too early to say what their role will be, but they’re certainly very promising. So I think it's better now than it has been in my professional lifetime.
Q: What are the most important lines of research that have developed in the past 5 or 10 years?
NW: I think the important research has been to get these drugs into practice, in the correct doses. For uncomplicated malaria: to find the best doses and combination treatments, and to also find the best ways of assessing them. There has been a lot of development in the whole field of clinical trials, how drugs are assessed in rural areas, how we can measure drugs in difficult places and so forth – so translating theoretical pharmacology, which is the study of drugs, into practice and through that, getting the right drug regiment. Same as severe malaria – if you look at the treatment of malaria today, it’s very different to that of ten years ago, and the important thing is, it now has a sound evidence base. In the past, the way we developed drugs was a little bit hit and miss, and I think it’s a lot better now.
Q: Why does your line of research matter, why should we put money into it?
NW: Well, malaria being the most important parasitic disease of humans has a huge humanitarian impact – it affects both the quality of life, and of course, life expectancy, and it has an enormous economic impact on developing countries. Some have said that negative growth in Africa (negative economic growth) can be ascribed to malaria itself. So clearly there’s a very strong argument for getting malaria under control and even trying to eliminate it, which is what we are now trying to do – at least in the South-East Asian region. I think it makes a lot of sense to attack this, because I think we can make substantial advances, and we have. I’m actually reasonably optimistic that this can continue, despite the threat of resistance.
Q: How does your research fit into Translational Medicine within the Department?
NW: Well we actually do research that makes a real difference to the practice of medicine. By doing investigations, clinical investigations and laboratory investigations, we’ve developed better treatments and then we have deployed them – shown that they are better than the previous treatments and safe, and this has been translated into policy and importantly into practice. So it really does go all the way from clinical investigation, through to the average treatment of malaria in the rural tropics.
This interview was recorded in May 2013.