A Phase 3 interventional study of High dose ultra short Primaquine and Placebo in Malaria, sponsored by Menzies School of Health Research. Not yet recruiting at 5 sites in 4 countries. Open to participants aged 5 Years and older. Per ClinicalTrials.gov, last updated 2026-03-12.
Sponsored by Menzies School of Health Research · Phase 3, Interventional, and Treatment
Current treatment regimens to prevent relapsing malaria are too long. A shorter higher dose treatment could improve treatment outcomes, but this needs to be balanced against increased risk of side effects. Recent data from a trial in children in Papua New Guinea (PNG) suggests a shortened treatment of 3 days is safe and effective. Our multicentre trial will assess the safety and efficacy of an ultra-short primaquine course. This trial is expected to directly influence global treatment policies.
1,184 studies on the registry are indexed under Malaria; 79 are open to participants now.
This study's planned enrollment of 1,019 is above the median of 252 across 937 interventional studies indexed under Malaria.
Browse Malaria studies →Menzies School of Health Research is the lead sponsor of 45 studies on the registry; 7 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this arm will receive a high-dose, short-course primaquine regimen (PQ7), consisting of a total dose of 7 mg/kg administered as 1 mg/kg once daily in the morning for 7 days (Day 0-6). A matching placebo will be given in the evening on the first three days (Day 0-2).
Drug: High dose ultra short Primaquine · Other: Placebo
Participants in this arm will receive a high-dose, ultra-short primaquine regimen (PQ3.5), consisting of a total dose of 7 mg/kg administered as 1 mg/kg twice daily for 3.5 days (Day 0-2 morning and evening doses, and Day 3 morning dose). A matching placebo will be given as the morning dose on Days 4-6.
Drug: High dose ultra short Primaquine · Other: Placebo
High-dose, ultra-short primaquine (PQ3.5): 7mg/kg total dose given as 1mg/kg twice daily over 3.5 days (day 0, 1 and 2 morning and evening doses, and day 3 morning dose) followed by placebo as morning doses on day 4, 5 and 6.
Matching placebo administered according to the arm schedule. Morning dose on Days 4-6 for PQ3.5 arm and Evening dose on the first 3 days for PQ 7 arm).
Incidence risk of any recurrent vivax parasitaemia within 4 months.
The incidence risk (time to first event) of any recurrent P. vivax parasitaemia within 4 months as determined by microscopy
Time frame: 4 Months
The incidence risk of any P. vivax parasitaemia within 6 months.
The incidence risk (time to first event) of any P. vivax parasitaemia within 6 months as determined by microscopy
Time frame: 6 months
Incidence of haemoglobin drop >25% to <7g/dl within 14 days of treatment.
Number of participants experiencing a haemoglobin decrease of \>25% from baseline resulting in Hb\<7g/dl
Time frame: 0-14 days
Incidence of moderate anaemia within 14 days after starting primaquine
Number of participants developing haemoglobin \>=5g/dl and \<7g/dl within 14 days after treatment initiation
Time frame: 0-14 days
Incidence of severe anaemia within 14 days after starting Primaquine
Number of participants developing haemoglobin \<5g/dl within 14 days of treatment initiation.
Time frame: 0-14 days
• The proportion of patients requiring blood transfusion within the 6 months follow up period.
Participants requiring transfusion due to haemolysis or severe anaemia
Time frame: 6 months
The incidence risk of symptomatic P. vivax parasitaemia within 4 months.
The incidence risk (time to first event) of symptomatic P. vivax parasitaemia within 4 months as determined by microscopy.
Time frame: 4 months
Proportion of adverse events within 14 days.
The number and proportion of adverse events within 14 days after start of treatment
Time frame: 14 days
The number and proportion of serious adverse events.
The number and proportion of serious adverse events.
Time frame: 6 Months
Plan to share: Yes — De-identified individual participant data (IPD) underlying the results reported in this trial will be shared. This will include baseline characteristics, outcome measures, and adverse events data. Data will be available beginning [6-12 months] after publication of the primary results, and will be shared with qualified researchers upon reasonable request, following approval of a research proposal and completion of a data access agreement. Supporting documents such as the study protocol and statistical analysis plan will also be provided.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report
Access criteria: All the investigators involved in the study.
No publications or documents are linked to this record.
Start is estimated for Jun 2026; primary completion for Dec 2027, 18 months later.
Of 44 non-industry phase 3 interventional studies under Malaria, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 20 and three quarters within 34. This study's planned 18 months is below that.
Counting every sponsor, half of 50 studies reached it within 23 months; a quarter within 17 and three quarters within 31.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
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Menzies School of Health Research