Artemisinin-naphthoquine combination versus chloroquine-primaquine to treat vivax malaria: an open-label randomized and non-inferiority trial in Yunnan Province, China

Background: Plasmodium vivax is the main malaria parasite in China, and China is now making efforts to eliminate malaria by 2020. Radical cure of vivax malaria is one of challenges for malaria elimination. The purpose is to evaluate the efficacy and safety of artemisinin-naphthoquine (ANQ) versus chloroquine-primaquine (CQ-PQ) in treatment of vivax malaria in Yunnan Province, China. Methods: An open-label randomized and non-inferiority design, eligible patients with monoinfections of P. vivax were randomly assigned to receive either a total target dose of ANQ 24.5 mg/kg (naphthoquine 7 mg/kg and artemisinin 17.5 mg/kg), once a day for three days, or a total CQ dose of 24 mg base/kg, once a day for three days plus a PQ dose of 0.45 mg base/kg/day, once a day for eight days. Patients were followed up for one year. The difference in efficacy between ANQ and CQ-PQ was compared via Wilson's test. Results: By day 42, the number of patients free of recurrence was 125 (98.4%; 95% Confidence interval, 94.4-99.8%) for ANQ arm and 123 (96.1%; 95%CI, 91.1-98.7%) for CQ-PQ, and non-significant (P = 0.4496). By day 365, the number was 101 (79.5%; 95%CI, 71.8-85.9%) for ANQ and 106 (82.8%; 95%CI, 75.1-88.9%) for CQ-PQ, and non-significant (P = 0.610). So the proportions of patients free of recurrence had no significant difference between ANQ and CQ-PQ groups by day 28, 42 and 365; compared with CQ-PQ, the side effect of ANQ was mild. Conclusion: ANQ is non-inferior to CQ-PQ in terms of patients free of recurrence, and safer than CQ-PQ.