The 2015 Nobel Prize winners for Medicine has been awarded to the scientists who developed 2 major medicines that are now in widespread use against filarial nematodes and malaria. This award should be widely celebrated. But did you know that there is more to the story of one of the two medicines in the Nobel citation?
Artemether is a derivative of artemisinin – the medicine that won the prize for its discoverer. Back in 2000 I co-authored a paper with colleagues from the SwissTPH that reviewed the evidence of the effects of artemether on Schistosoma japonicum infections. Schistosoma spp is a type of helminth parasite (a trematode) that is often endemic in areas where malaria is present. The adult parasites inhabit the blood stream and could therefore be exposed to metabolites of artemether. Evidence from the trials reviewed in that paper suggested some element of prophylactic effect of the drug on Schistosoma japonicum after repeated treatments.
Praziquantel is still the drug of choice for treatment of schistosome parasites but it does not affect juvenile stages. People recurrently exposed to schistosoma infections may have multiple stages at one time distributed by stage of development in the skin, bloodstream, liver, with adult worms residing in veins near the gut or bladder depending on species. Parasite eggs secreted by the parasites may be distributed more widely around the bladder, gut, urogenital tract depending on species.
Artemsisinin derivatives have been shown to be effective against juvenile stages of the schistosoma parasite, but the results of clinical trials since that early review with which I was involved, including combination therapies with praziqiuantel and other drugs, have not produced consistently clear results, so of course we need more research on what is happening within individuals who are exposed to co-infections of malaria, helminths etc.
I doubt any more research into the added benefits of artemether will lead to another Nobel Prize. But don’t be disheartened by the fact that the medicine horse has already bolted. The same horse needs constant care and attention to become an unbeatable champion, racing against parasites that have co-evolved and are quite capable of resisting our best efforts.
I am an epidemiologist based at a UK Higher Education establishment (Durham University, if you are interested). My research interests are primarily within the domain of Neglected Tropical Diseases (NTDs). I believe that the only way we can effectively tackle complex problems affecting populations living in tropics and sub-tropics is through trans-disciplinary collaboration. My working definition of transdisciplinary is undertaking research alongside so-called 'stakeholders' - groups and individuals who do not call themselves 'researchers' but whose experiences and knowledge can be used to great effect when combined with the experiences and knowledge of the research community. You can read my online CV at the link below.