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Competing Interests: We declare no competing interests. We both acknowledge support from the grant CEX2018-000806-S funded by the Spanish Ministry of Science and Innovation (MCIN), through the Research State Agency (AEI; MCIN/AEI/10.13039/​501100011033), and support from the Generalitat de Catalunya through the CERCA Program. QB's institution (CISM) is supported by the Government of Mozambique and the Spanish Agency for International Development (AECID). We also acknowledge the support of Fundación Ramón Areces to ISGlobal's Program on the Molecular Mechanisms of Malaria.

Mass drug administration (MDA) with monthly dihydroartemisinin-piperaquine (DHA-PQP) appears useful in malaria control and elimination strategies. Determining the relationship between consecutive piperaquine phosphate (PQP) exposure and its impact on QT interval prolongation is a key safety consideration for MDA campaigns. Healthy volunteers from Papua New Guinea received a 3-day course of DHA-PQP (2.1/17.1 mg/kg) monthly for 3 consecutive months in a single arm longitudinal study. Plasma PQP concentrations were measured after the third dose of each course (at 52-54 h) and at 0 h of course 3. Twelve-lead electrocardiographic readings were conducted at 0 h, 48 h, 52 h, and day 7 of each course. QT interval corrected by Fridericia's formula (QTcF) was measured at each time point. A pharmacokinetic-pharmacodynamic model using nonlinear mixed effects models was developed to correlate PQP concentrations with QTcF. Ten thousand female and 10,000 male individuals were simulated at each treatment course. Eighty-two participants were included; mean age was 28.3 years (standard deviation [SD] ±12.3 years), and 36 (44%) were female. Pharmacokinetic-pharmacodynamic models were determined with 290 PQP concentrations and 868 QTcF observations. The average baseline QTcF was 392 ms with a between-subject variability SD ±14.4 ms and between-occasion variability SD ±3.64 ms. From the population modeled, only 0.08% of males and 0.45% of females would be at risk of an absolute QTcF of >500 ms. DHA-PQP is safe at standard doses in consecutive months, and the likelihood of severe cardiac events occurring during an MDA campaign is very low. This study has been registered at ClinicalTrials.gov under identifier NCT02605720.

Mass drug administration (MDA) of sequential rounds of antimalarial drugs is being considered for use as a tool for malaria elimination. As an effective and long-acting antimalarial, dihydroartemisinin-piperaquine (DHA-PQP) appears to be suitable as a candidate for MDA. However, the absence of cardiac safety data following repeated administration hinders its use in the extended schedules proposed for MDA. We conducted an interventional study in Lihir Island, Papua New Guinea, using healthy individuals age 3 to 60 years who received a standard 3-day course of DHA-PQP on 3 consecutive months. Twelve-lead electrocardiography (ECG) readings were conducted predose and 4 h after the final dose of each month. The primary safety endpoint was QT interval correction (QTc using Fridericia's correction [QTcF]) prolongation from baseline to 4 h postdosing. We compared the difference in prolongations between the third course postdose and the first course postdose. Of 84 enrolled participants, 69 (82%) participants completed all treatment courses and ECG measurements. The average increase in QTcF was 19.6 ms (standard deviation [SD], 17.8 ms) and 17.1 ms (SD, 17.1 ms) for the first-course and third-course postdosing ECGs risk difference, -2.4 (95% confidence interval [95% CI], -6.9 to 2.1; P = 0.285), respectively. We recorded a QTcF prolongation of >60 ms from baseline in 3 (4.3%) and 2 (2.9%) participants after the first course and third course ( P = 1.00), respectively. No participants had QTcF intervals of >500 ms at any time point. Three consecutive monthly courses of DHA-PQP were as safe as a single course. The absence of cumulative cardiotoxicity with repeated dosing supports the use of monthly DHA-PQP as part of malaria elimination strategies., (Copyright © 2018 American Society for Microbiology.)