High-dose daily and weekly primaquine for vivax malaria in people with reduced G6PD activity

Primaquine for Vivax Malaria in G6PD Intermediate and Deficient Cases.

Phase 4 Interventional Menzies School of Health Research · NCT07468513

This will test whether 1 mg/kg daily primaquine for 7 days is safe and works for adults with P. vivax and intermediate G6PD, and whether 0.75 mg/kg weekly primaquine is safe and works for adults with G6PD deficiency.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years and up
SexAll
SponsorMenzies School of Health Research Academic / other
Locations4 sites (Manaus and 3 other locations)
Trial IDNCT07468513 on ClinicalTrials.gov

What this trial studies

This non-randomized observational study enrolls adults with P. vivax mono-infection who have reduced G6PD enzyme activity and separates them into intermediate (30–<70% activity) and deficient (<30%) groups. Patients with intermediate activity receive schizontocidal therapy plus primaquine 1 mg/kg daily for 7 days, while deficient patients receive schizontocidal therapy plus primaquine 0.75 mg/kg once weekly for 8 weeks. Participants are followed for six months to monitor safety (including hemolysis and hemoglobin changes) and recurrence of parasitemia. The study is conducted at sites in Brazil, Ethiopia, and Papua New Guinea in collaboration with Menzies School of Health Research, Curtin University, University of Melbourne, and Arba Minch University.

Who should consider this trial

Good fit: Adults (≥18) with P. vivax mono-infection, fever or recent fever, hemoglobin ≥8 g/dL, and confirmed G6PD intermediate (30–<70%) or deficient (<30%) status who live near the study sites and consent to six months of follow-up are ideal candidates.

Not a fit: Pregnant or breastfeeding women, patients with severe malaria, those regularly taking hemolysis-inducing drugs, people with known hypersensitivity to study drugs, children under 18, and those with hemoglobin <8 g/dL are unlikely to be eligible or to benefit.

Why it matters

Potential benefit: If successful, this approach could expand safe radical cure options for vivax malaria in people with reduced G6PD and reduce relapse rates.

How similar studies have performed: Primaquine radical cure is well established in G6PD-normal patients and weekly primaquine has supportive evidence in G6PD-deficient individuals, but high-dose daily primaquine in intermediate G6PD patients is less well studied.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* • P. vivax peripheral parasitaemia (mono-infection)

  * G6PD intermediate or deficient status (G6PD activity 30-\<70% or ≤30% of the adjusted male median as determined by the Standard G6PD (SDBioline, ROK))
  * Fever (temperature ≥37.5⁰C) or history of fever in the preceding 48 hours
  * Age ≥18 years
  * Haemoglobin at presentation ≥8g/dl
  * Written informed consent
  * Living in the study area and willing to be followed for six months.

Exclusion Criteria:

* • Danger signs or symptoms of severe malaria

  * Pregnant or lactating females
  * Regular use of drugs with haemolytic potential
  * Known hypersensitivity to any of the study drugs.

Where this trial is running

Manaus and 3 other locations

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Vivax MalariaG6PD DeficiencyPrimaquine in G6PD deficiencyVivax malaria in G6PD deficient patients
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.