GSK and Medicines for Malaria Venture (MMV) have introduced tafenoquine, a single-dose medicine, in Brazil and Thailand to prevent the relapse of Plasmodium vivax (P. vivax) malaria.

Tafenoquine, an eight-aminoquinoline derivative, is said to effectively target all stages of the P. vivax lifecycle, including hypnozoites.

In 2008, GSK initiated a collaboration with MMV, a Swiss non-profit organisation, to advance tafenoquine as an anti-relapse drug for patients infected with P. vivax.

Tafenoquine is co-administered with chloroquine, for radical cure.

The combination is used for the blood-stage infection to treat both blood- and liver-stages of the disease.

Due to its classification as an eight-aminoquinoline, tafenoquine has the potential to induce acute haemolytic anaemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Therefore, a G6PD test is mandatory before prescribing the drug.

The Ministries of Health in Thailand and Brazil have funded feasibility studies on the regular use of tafenoquine following point-of-care G6PD testing within their public health systems, supported by MMV.

Evidence from these real-world studies has supported the decisions to implement these anti-malarial tools as part of their efforts to eradicate malaria.

GSK chief global health officer Thomas Breuer said: “Working together with MMV and PATH through the Partnership for Vivax Elimination (PAVE) to optimise this new treatment option has been fundamental to countries being able to introduce this new tool.”

In response to the severe public health crisis in the Yanomami Special Indigenous Health District (DSEI), the Brazilian government expedited the introduction of tafenoquine in March 2024.

The implementation of this new testing and treatment option has commenced within the broader public health system (SUS).

On the other hand, Thailand reported a substantial rise in malaria cases in recent years, increasing the demand for malaria diagnosis and treatment resources.

MMV CEO Martin Fitchet said: “This demonstrates real leadership by the governments of Brazil and Thailand in bringing innovation to accelerate the elimination of malaria, MMV is proud to have collaborated with GSK and PATH on the development of this important medicine.”

Tafenoquine has received approvals in the US, Australia, Brazil, Ethiopia, Guyana, Peru, Thailand, Colombia, and the Philippines.

It is currently undergoing marketing authorisation evaluation in several other countries where P. vivax malaria is prevalent.