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Evaluation of the Gametocytocidal Efficacy and Safety of Primaquine in Uncomplicated Falciparum Malaria in Uganda

Phase 3
Completed
Conditions
Falciparum Malaria
Interventions
Registration Number
NCT01365598
Lead Sponsor
London School of Hygiene and Tropical Medicine
Brief Summary

The purpose of this study is to evaluate the safety and efficacy of lower doses of primaquine compared to the dose recommended by the WHO for reducing P. falciparum gametocytes in the infected human host to prevent transmission of falciparum malaria to the anopheles mosquito vector.

Detailed Description

A single dose of 0.75mg/kg primaquine base is recommended by the WHO to block transmission of falciparum malaria from infected humans to mosquitoes by clearing gametocytes. However, the optimal dose for safety and efficacy has not been evaluated. Dose-finding data is important because primaquine has a dose-dependent risk of causing haemolysis (destruction of blood cells) in pre-disposed individuals, such as those with G6PD deficiency. G6PD deficiency is most prevalent in malaria-endemic areas. Therefore, it is essential that data on primaquine's safety is available in such areas.

The investigators hypothesise that lower doses of primaquine have a lower risk of adverse effects compared to the WHO-recommended dose, but retain the transmission-blocking efficacy.

The investigators propose to test this hypothesis in a four-arm clinical trial with a non-inferiority design to evaluate the efficacy and a superiority design to evaluate the safety of the WHO dose (0.75mg/kg) and lower doses of primaquine for clearance of P. falciparum gametocytes in children in Uganda. The study will include a pharmacokinetic analysis.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
468
Inclusion Criteria
  • Age >/= 1 year and </= 10 years
  • Weight over 10kg
  • Fever >38 degrees C (tympanic) or history of fever in the last 24 hours
  • P. falciparum parasitaemia <500 000/µl
  • Normal G6PD enzyme function
Exclusion Criteria
  • Enrolled in another study
  • Evidence of severe illness/ danger signs
  • Known allergy to study medications
  • Haemoglobin < 8g/dL)
  • Started menstruation
  • Pregnancy or breastfeeding
  • Primaquine taken within the last 4 weeks
  • Blood transfusion within the last 90 days
  • Non-falciparum malaria co-infection

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
PlaceboPrimaquineNon-active drug
Low dose primaquine (PQ1)PrimaquineLowest experimental dose of primaquine base: 0.1mg/kg
Reference dose primaquine (PQ-R)PrimaquineWHO-recommended dose of primaquine base: 0.75mg/kg
Intermediate dose primaquine (PQ2)PrimaquineIntermediate experimental dose of primaquine base: 0.4mg/kg
Primary Outcome Measures
NameTimeMethod
Mean (+/- SD) maximal fall in Hb (g/dL) from enrollment to day 28 of follow-up28 days

Mean maximal greatest negative difference in Hb (measured by Hemocue®) from enrollment value per treatment arm over 28 days follow up

Mean number of days to gametocyte clearance (gametocyte clearance time, GCT)14 days

Mean number of days per treatment arm for gametocytes to become undetectable using sub-microscopic molecular testing methods (real-time nucleic acid sequence-based amplification, QT-NASBA)and interpolated from measured data points.

Secondary Outcome Measures
NameTimeMethod
Incidence of serious adverse events by sign, symptom, laboratory parameter and relationship to taking study drug28 days

Percentage (number) per treatment arm during days 0-28

Mean (+/- SD) area under the curve of gametocyte density per day during 14 days of follow-up14 days

An estimate of the area under the curve of gametocytes (measured by QT-NASBA) seen over time, averaged per day of follow up (days 0-14) and interpolated from measured data points

Requirement for blood transfusion28 days

Percentage of children receiving blood transfusion per treatment arm during days 0-28

Follow-up day of Hb nadir28 days

Mean day of follow up (day 0-28) per treatment arm of lowest Hb measurement (by Hemocue®)

Incidence of gastrointestinal symptoms after taking study drug6 days

Percentage (number) of children with gastrointestinal symptoms per treatment arm during days 2-7

Trial Locations

Locations (1)

Walukuba Health Centre IV

🇺🇬

Jinja, Eastern Region, Uganda

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