GSK plc and Medicines for Malaria Venture (MMV) have announced that the first single-dose medicine for the prevention of relapse of Plasmodium vivax (P. vivax) malaria – tafenoquine, co-administered with chloroquine for radical cure, has now been launched in both Thailand and Brazil, in support of malaria elimination efforts.

P. vivax is the dominant malaria parasite in most countries outside of sub-Saharan Africa.It is characterised by clinical relapses, with patients repeatedly falling sick unless the latent liver-stage infection is treated. This takes a considerable physical, economic and social toll on patients and communities, perpetuating cycles of poverty. In some cases, relapses can lead to severe malaria and death. Relapses also increase the disease burden and the potential for onward transmission, ultimately impeding global efforts to eliminate malaria.

Tafenoquine is an 8-aminoquinoline, antimalarial drug targeting the liver-stage of P. vivax malaria. When used in combination with chloroquine for the blood-stage infection, tafenoquine provides what is known as radical cure: the treatment of both the blood- and liver-stages of the disease. Tafenoquine, like all 8-aminoquinolines, has the potential to cause acute haemolytic anaemia in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency, therefore a G6PD test must be performed before prescribing.

The Ministries of Health in both Thailand and Brazil sponsored feasibility studies on the routine use of tafenoquine after point-of-care G6PD testing within their public health systems, with the support of MMV. Evidence from these real-world studies has informed their decisions to introduce these anti-malarial tools in their drive to help eliminate malaria.