Short COurse PrimaquinE for the radical cure of P. vivax (SCOPE)

Although prevention of relapses is crucial for reducing transmission of P. vivax malaria, only two relapse-prevention drugs (primaquine and tafenoquine) are licenced. Primaquine (PQ) is the anti-relapse drug currently available in most endemic regions, but its widespread impact on health outcomes is limited by poor adherence to the standard 14-day course and concerns over the risk of drug induced haemolysis in patients with G6PD deficiency.

Previously, assessing whether patients were G6PD deficient was difficult outside of well-equipped medical laboratories. The STANDARD G6PD Test, a quantitative, point-of-care test is now available and able to quickly determine the G6PD activity in patients’ red blood cells to guide the selection of the most appropriate treatment regimen with either primaquine or tafenoquine.

For patients with normal G6PD activity levels, one treatment regimen is short-course (7 days), high-daily-dose primaquine, which initial studies have shown to have similar efficacy compared with the same WHO-recommended total dose of 7mg/kg body weight administered over 14 days in areas with high risk of relapse. This shorter primaquine regimen can lead to better adherence compared to the standard 14-day regimen and thus to fewer relapses. However, in some studies, the higher daily dose in the 7-day regimen (1mg/kg) is associated with more adverse events, particularly an increased risk of haemolysis and gastrointestinal events.

The WHO has highlighted the need for additional evidence on the safety of short-course (7 days), high-daily-dose primaquine. These Unitaid-supported studies aim to contribute to addressing this knowledge gap.

The study has two stages:

• Stage 1 will provide preliminary data from 4 study clinics on the safety and feasibility of short course (7-day), high-daily dose primaquine (PQ7) in patients with normal (>70%) G6PD activity. Following the conclusion of stage 1, a stringent safety assessment will be conducted to decide whether to proceed to stage 2. Assuming the decision is taken to move ahead following the safety review, the evidence gathered during stage 1 will be used to inform the main implementation which will take place in stage 2.
• Stage 2 will study the cost-effectiveness and feasibility of routine implementation of G6PD testing, the revised treatment algorithm, patient education, supervision of the first dose and community review on day 3 at all 10 study clinics.

Project DetailsSCOPE IndonesiaSCOPE Papua New Guinea

Financing & Economics
P. vivax

Jul 2023

Indonesia
Papua New Guinea