Published: July 18, 2019
Taylor WRJ*, Thriemer K*, von Seidlein L, Yuentrakul P, Assawariyathipat T, Assefa A, Auburn S, Chand K, Chau NH, Cheah PY, Dong LT, Dhorda M, Degaga TS, Devine A, Ekawati LL, Fahmi F, Hailu A, Hasanzai MA, Hien TT, Khu H, Ley B, Lubell Y, Marfurt J, Mohammad H, Moore KA, Naddim MN, Pasaribu AP, Pasaribu S, Promnarate C, Rahim AG, Sirithiranont P, Solomon H, Sudoyo H, Sutanto I, Thanh NV, Tuyet-Trinh NT, Waithira N, Woyessa A, Yamin FY, Dondorp A, Simpson JA, Baird JK, White NJ, Day NP†, Price RN†. Short-course primaquine for the radical cure of Plasmodium vivax malaria: a multicentre, randomised, placebo-controlled non-inferiority trial. The Lancet. 18/07/2019. DOI:https://doi.org/10.1016/S0140-6736(19)31285-1
Primaquine is the only widely used drug that prevents Plasmodium vivax malaria relapses, but adherence
to the standard 14-day regimen is poor. We aimed to assess the efficacy of a shorter course (7 days) of primaquine for
radical cure of vivax malaria.
We did a randomised, double-blind, placebo-controlled, non-inferiority trial in eight health-care clinics
(two each in Afghanistan, Ethiopia, Indonesia, and Vietnam). Patients (aged ≥6 months) with normal glucose-6-
phosphate dehydrogenase (G6PD) and presenting with uncomplicated vivax malaria were enrolled. Patients were
given standard blood schizontocidal treatment and randomly assigned (2:2:1) to receive 7 days of supervised
primaquine (1·0 mg/kg per day), 14 days of supervised primaquine (0·5 mg/kg per day), or placebo. The primary
endpoint was the incidence rate of symptomatic P vivax parasitaemia during the 12-month follow-up period, assessed
in the intention-to-treat population. A margin of 0·07 recurrences per person-year was used to establish noninferiority of the 7-day regimen compared with the 14-day regimen. This trial is registered at ClinicalTrials.gov (NCT01814683).
Between July 20, 2014, and Nov 25, 2017, 2336 patients were enrolled. The incidence rate of symptomatic
recurrent P vivax malaria was 0·18 (95% CI 0·15 to 0·21) recurrences per person-year for 935 patients in the 7-day
primaquine group and 0·16 (0·13 to 0·18) for 937 patients in the 14-day primaquine group, a difference of 0·02
(–0·02 to 0·05, p=0·3405). The incidence rate for 464 patients in the placebo group was 0·96 (95% CI 0·83 to 1·08)
recurrences per person-year. Potentially drug-related serious adverse events within 42 days of starting treatment were
reported in nine (1·0%) of 935 patients in the 7-day group, one (0·1%) of 937 in the 14-day group and none of 464 in
the control arm. Four of the serious adverse events were significant haemolysis (three in the 7-day group and one in
the 14-day group).
In patients with normal G6PD, 7-day primaquine was well tolerated and non-inferior to 14-day
primaquine. The short-course regimen might improve adherence and therefore the effectiveness of primaquine for
radical cure of P vivax malaria.
UK Department for International Development, UK Medical Research Council, UK National Institute for
Health Research, and the Wellcome Trust through the Joint Global Health Trials Scheme (MR/K007424/1) and the
Bill & Melinda Gates Foundation (OPP1054404).