The competitive product Artequick which the Chinese launched against Coartem and Coarsucam is now confronted by resistance like any other monotherapy. A letter to the editor by DL Saunders et al., in NEJM July 2014 describes the dihydroartemisinin-piperaquine failure in Cambodia. The drug was adopted as first line treatment in this country in 2010. Three years later the efficacy has decreased from 92% to 64%. At 72 hours 56% of patients still had persistent parasitemia. Another research team (R Leang et al., Antimicrobial Agents and Chemotherapy, May 2015, doi:10.1128/AAC) assessed the clinical efficacy of dihydroartemisinin-piperaquine in uncomplicated falciparum malaria in western and eastern Cambodia over 42 days. The proportion of patients with recrudescent infections was significantly higher in western (15.4%) compared to eastern Cambodia (2.5%). Delayed parasite clearance after treatment with dihydroartemisinin-piperaquine in Plasmodium falciparum malaria patients was also noticed in Central Vietnam (Thriemer et al., Antimicrobial Agents and Chemotherapy, 2014, 58, 7049-55).
A disaster for Cambodia and Vietnam now, but a genocide looming for African countries, after the failure of other ACTs.
WHO believes that increasing treatment failures are "most probably due to piperaquine resistance," according to Pascal Ringwald, coordinator of WHO's Drug Resistance and Containment program. Researchers at the University of Uppsala indicated (Science Translational Medicine, 30 Oct 2014) that even moderate resistance to piperaquine can be expected to drastically compromise the usefulness of piperaquine in preventive therapy.