Dihydroartemisinin-piperaquine With Low Dose Primaquine to Reduce Malaria Transmission
Status:
Completed
Trial end date:
2015-12-01
Target enrollment:
Participant gender:
Summary
Primaquine (PQ) is currently the only available drug that can clear the mature transmission
stages of P. falciparum parasites. PQ was previously shown to clear gametocytes that persist
after artemisinin-combination therapy. A major caveat to the use of primaquine in mass
adminsitrations for the reduction of malaria transmission is that metabolism of the drug in
individuals with glucose-6 phosphate dehydrogenase (G6PD) deficiency can lead to transient
haemolysis. The haemolytic side effect of PQ is dose-related. Haemolysis is more commonly
observed after prolonged PQ treatment but has also been observed in African populations
following a single dose of PQ. This haemolysis was self-limiting, largely restricted to G6PD
deficient individuals and did not lead to clinical symptoms. Nevertheless, any drug-induced
haemolysis is reason for concern and the World Health Organization has therefore reduced the
recommended dose of single low dose primaquine from 0.75mg/kg to 0.25mg/kg. This dosage is
deemed safe without prior G6PD or Hb screening. However, there is limited direct evidence on
the extent to which this dosage of PQ prevents malaria transmission to mosquitoes.
In the current study, the investigators will assess the efficacy of DP in combination with
low-dose PQ to prevent onward malaria transmission. The investigators will perform the
investigators study in individuals aged 5-15 years who are carry microscopically detectable
densities of P. falciparum gametocytes. This age group is chosen because asexual parasite
carriage and gametocyte carriage are common in this age group. All enrolled individuals will
receive a full three-day course of DP, and will be randomized to receive a dose of primaquine
or placebo with their third dose. Efficacy will be determined based on gametocyte carriage
during follow-up, measured by molecular methods. For all individuals, the effect of treatment
on infectivity to mosquitoes will be assessed by membrane feeding assays at two time points.
Phase:
Phase 3
Details
Lead Sponsor:
London School of Hygiene and Tropical Medicine
Collaborators:
International centre for Insect Physiology and Ecology (ICIPE) International Centre of Insect Physiology and Ecology (ICIPE) Radboud University