Last Updated: 12/03/2026

Southeast Asia Dose Optimization of Tafenoquine (SEADOT) Study

Objectives

The primary objective of this study is to determine whether a 50% increase in tafenoquine dose (TQ-higher) provides better efficacy than the currently recommended tafenoquine dose (TQ-current) as measured by the absence of recurrent P. vivax infection by 4 months

Secondary Objectives:

  • Characterise the safety and tolerability of a 50% higher tafenoquine dose (TQ-higher)
  • Characterise TQ population PK and PD and correlate the CYP2D6 metaboliser status and genotype with TQ concentrations in vivo
  • Characterise the best predictors of recurrence at day 28 and month 4
Principal Investigators / Focal Persons

Cindy Chu

Rationale and Abstract

In East Asia and Oceania, Plasmodium vivax is the most common cause of malaria. Relapses occur in over half the infections and comprise the main burden of P. vivax malaria. Relapses are the major cause of morbidity, particularly in children and pregnant women. In recent years, targeted malaria elimination has driven down Plasmodium falciparum malaria in these populous regions, but P. vivax malaria has re-emerged rapidly because of relapse. Preventing relapse (radical cure) requires administration of an 8-aminoquinoline – which until recently meant a 7-14 day course of primaquine. Tafenoquine is a recently registered slowly eliminated 8-aminoquinoline with the substantial operational advantage of providing single dose radical cure. However, phase 3 randomized controlled trials showed that the currently recommended 300mg adult dose (~5mg/kg) of tafenoquine had low radical curative efficacy against P. vivax malaria. Tafenoquine doses up to 14mg/kg have proved safe and well tolerated in adults and children with >70% G6PD activity.

Date

Sep 2023 — Aug 2028

Total Project Funding

$3.59M

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