Start of ARCTIC, a feasibility study of a new Plasmodium vivax malaria treatment protocol in Thailand

22 Jul 2022

ARCTIC will explore the operational feasibility of quantitative G6PD testing prior to treatment with tafenoquine or primaquine.

Dr Aungkana delivering training to healthworkers

On 22 May, the Division of Vector Borne Diseases (DVBD) within the Thai Ministry of Public Health, with the support of Medicines for Malaria Venture (MMV) enrolled the first patients in the ARCTIC study. ARCTIC (Assessing Radical Cure Treatment In routine Care) is an operational feasibility study looking at the real-world use of point-of-care, Glucose-6-Phosphate Dehydrogenase (G6PD) testing and appropriate radical cure treatment with tafenoquine (TQ) or primaquine (PQ). This is the first such study using single-dose tafenoquine in the Asia-Pacific region and should provide evidence to the Thai Ministry of Public Health on the potential role for these tools in supporting the country’s 2024 malaria elimination goal.

ARCTIC is taking place in the Yala and Mae Hong Son provinces, where quantitative G6PD testing has been available for routine use prior to providing PQ treatment for P. vivax malaria relapse prevention at district hospitals and malaria clinics since 2020. Like primaquine, tafenoquine causes dose-dependent haemolysis in individuals who are glucose-6-phosphate dehydrogenase deficient, so testing individuals to ascertain their G6PD status prior to treatment is important for patient safety. Before the study start, the relevant staff at all participating sites were re-trained on the quantitative G6PD test procedure and the radical cure treatment protocol. 

The study will take place in two phases, starting initially in higher-level health facilities such as hospitals, and expanding to lower-level malaria clinics after an assessment by an Independent Study Oversight Committee. This assessment will be based on an interim analysis to be conducted with data from the first 40 patients seen at the higher-level facilities. It is anticipated that it will take a total of about 6 months to complete data collection at the study sites. 

Dr David Reddy, MMV’s CEO said,

Thailand is leading the way towards malaria elimination in the Greater Mekong subregion. We are excited to be working with the Ministry of Public Health to study the roll out of quantitative G6PD testing and single-dose tafenoquine, tools we believe can increase treatment adherence and reduce the burden of P. vivax – a particularly difficult malaria species to eliminate.