The WHO’s Global Technical Strategy for Malaria 2016–2030 has set the ambitious target of eliminating malaria from at least 35 countries by 2030. A major challenge in reaching this target is the elimination of Plasmodium vivax, a species of malaria that accounts for half of all cases outside sub-Saharan Africa. To support WHO’s goals, GSK and MMV have developed tafenoquine, a single-dose treatment for the radical cure of P. vivax malaria.
Supporting access to diagnostics and G6PD test
Tafenoquine is an 8-aminoquinoline drug. As such, it raises concerns about possible haemolysis in patients deficient in the glucose-6-phosphate dehydrogenase (G6PD) enzyme. Limited access to G6PD tests makes it difficult for physicians to prescribe the drugs.
MMV and PATH are leading a joint initiative, VivAccess, to address the challenges associated with P. vivax malaria. VivAccess aims to support access to a suite of products such as malaria diagnostics, G6PD diagnostics, medicines to treat the symptoms of P. vivax malaria and medicines to treat malaria relapse.
Feasibility studies are planned in Brazil and in Thailand in 2020–2021 to assess the operational feasibility of introducing a G6PD test before appropriate radical cure at various levels of the health services. These initiatives will help to inform potential adoption of tafenoquine in other countries affected by P. vivax malaria.
Improving access to tafenoquine
Guided by the leadership of national health agencies, VivAccess will also provide support in terms of market analytics, technical expertise and product delivery coordination as countries seek to introduce effective radical cure into national malaria protocols and accelerate progress towards malaria elimination goals.
In addition, mathematical modelling has been conducted to assess the potential public health impact of introducing tafenoquine as part of malaria case management to prevent P. vivax relapses in Brazil. Cost-effectiveness studies are ongoing to inform Health Technology Assessment in Brazil. They should be completed by November 2021.
Towards a formulation of tafenoquine for children
The development of a paediatric formulation of tafenoquine is ongoing. The results of a paediatric pharmacokinetic bridging study have been finalized and will be submitted to the Australia TGA at the end of 2020.