Comparing treatments for Plasmodium vivax malaria

Does Artemisinin Combination Treatment Reduce the Radical Curative Efficacy of High Dose Tafenoquine for Plasmodium Vivax Malaria?

Phase 4 Interventional Shoklo Malaria Research Unit · NCT05788094

This study is testing whether a new malaria treatment called tafenoquine works better when combined with other antimalarial drugs for people with Plasmodium vivax malaria.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment606 (estimated)
Ages18 Years and up
SexAll
SponsorShoklo Malaria Research Unit Academic / other
Locations1 site (Mae Sot, Changwat Tak)
Trial IDNCT05788094 on ClinicalTrials.gov

What this trial studies

This clinical trial evaluates the effectiveness of different treatment regimens for Plasmodium vivax malaria, focusing on the use of tafenoquine in combination with various antimalarial therapies. The study aims to determine whether artemisinin combination therapy (ACT) may interfere with the efficacy of tafenoquine, a single-dose medication that targets the liver stages of the malaria parasite. Participants will be monitored for four months to assess treatment outcomes and potential relapses. The trial is set in the Greater Mekong Subregion, an area significantly affected by this type of malaria.

Who should consider this trial

Good fit: Ideal candidates for this study are adults over 18 years old with a confirmed diagnosis of P. vivax mono-infection and adequate G6PD enzyme activity.

Not a fit: Patients with concurrent P. falciparum malaria, severe anemia, or those who are pregnant or lactating will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a more effective and convenient treatment option for patients suffering from Plasmodium vivax malaria, potentially reducing relapse rates.

How similar studies have performed: Previous studies have indicated the potential effectiveness of tafenoquine, but this specific comparison with ACT is novel and has not been extensively tested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients with P. vivax mono-infection as diagnosed by Rapid Diagnostic Test
* Fever or history of fever in the previous 7 days
* Quantitative G6PD activity ≥70% of the population median i.e., ≥6.1U/gHb
* Age \> 18 years, Weight \>35 kg
* Ability to understand the study instructions and provide informed consent
* Willing to be followed for 4 months and likely to adhere to the study protocol.

Exclusion Criteria:

* Coincident P. falciparum malaria or other infections
* Pregnancy
* Lactation
* Hb \< 8 g/dL
* Quantitative G6PD activity \<70% of the population median i.e., \<6.1U/gHb
* Severe malaria (as per WHO guideline)
* History of allergic or haemolytic response to any of the study drugs

Where this trial is running

Mae Sot, Changwat Tak

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions MalariaMalaria, VivaxPlasmodium Vivax Malariaartemisinin combination treatmenttafenoquinePlasmodium vivax malaria
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.