Background and rationale:
An estimated 300,000 babies are born with Sickle Cell Anaemia (SCA) annually. Affected children have chronic ill health and many suffer a premature death. Ill health is commonly precipitated by febrile illnesses including malaria. Antimalarial chemoprophylaxis is an important strategy, but current regimes are either sub-optimally effective (e.g., monthly sulphadoxine-pyrimethamine, SP) or difficult to adhere to (e.g., daily proguanil). The investigators propose dihydroartemisinin-piperaquine (DP) as the agent with the most potential to be used across Africa.
Objectives:
Our objective is to determine the efficacy, safety, uptake, and cost-effectiveness of malaria chemoprevention with weekly single day courses of DP vs monthly single day courses of SP in children with SCA in eastern and southern Africa.
Hypothesis:
The hypothesis is that weekly single day courses of DP, is safe and more efficacious, compared to monthly single day courses of SP, for the malaria chemoprevention in children with SCA in eastern and southern Africa.
Design:
This will a randomised, double-blind controlled parallel-group superiority trial of weekly single day courses of DP for an average of 18 months compared to monthly single-day courses of SP in SCA patients. The study will be conducted in Uganda and Malawi. Participants will be randomised to DP or SP (1:1), stratified by bodyweight and study centre. The study will also assess the acceptability and uptake of the two interventions, the safety and pharmacokinetics of weekly DP, the development of resistance to DP and cost-effectiveness. At the end of the study, this information will be used to inform regional health policy.
Sites:
Participants will be recruited from Jinja Regional Referral hospital and Kitgum General hospital in Uganda and Queen Elizabeth (Blantyre) hospital in Malawi.
Interventions:
The intervention will be oral DP administered weekly for an average of 18 months based on weight categories. DP will be provided as tablets of D-ARTEPP® (Guilin Pharmaceutical Co. Ltd) and administered as dihydroartemisinin (20mg) and piperaquine (160 mg) at approximate doses of dihydroartemisinin 2.5mg/kg/day and piperaquine 20mg/kg/day. The active control will be the current standard of care for chemoprevention in Uganda and Malawi - monthly single-dose SP (S=25mg/kg). The same manufacturer will provide SP as the generic SP (in 500/25mg scored tablets).
Other care:
In addition to the above-mentioned malaria regimens, the participants will receive the standard of care for Sickle Cell Anaemia (including parental education on care, treatment for both the acute and chronic complications of Sickle Cell Anaemia, and daily penicillin prophylaxis if \<5 years).
Sample size:
With the minimum incidence rate of clinical malaria in SCA patients receiving monthly SP estimated at 0.2 events per year, and an effect size of 50% if DP is used, at a power of 0.9 and 0.05 level of significance, followed up for 18 months and allowing for 20% losses to follow up, and one interim analysis, the investigators will need 548 participants (274 in either arm) followed up for an average 18 months or until 824 person-years.
Follow up:
Participants will be followed for up for an average of 18 months or until 412 person-years of observation is achieved in each group (a combined total of 824 person-years of observation). This will be achieved by following between 548 and 824 participants for an average of 12 to 18 months each.
Outcome measures:
The primary efficacy outcome measures will be the incidence of clinical malaria. Secondary efficacy outcomes will include the incidence of malaria parasitaemia, all-cause sick-child clinic visits, SCA-related vaso-occlusive events (including severe pain events and dactylitis), acute chest syndrome, stroke, hospitalisations, blood-transfusions, and death.
Secondary safety outcome measures: QTc-prolongation on ECG recordings and incidence of serious cardiac adverse events (e.g., convulsions or syncope within 48 hours after drug intake). Tolerance: % vomiting drug within 30 minutes of administration. Others are cost-effectiveness, development of resistance to piperaquine, feasibility, acceptability, and uptake.
Data Analysis: Primary analysis will be by intention to treat. Incidence rates will be calculated, and rate ratios estimated using Poisson regression, with treatment (as randomised) as the predictor variable and the stratification factors site and weight-band as covariates.
