An Interventional Study to Compare the Efficacy and Safety of Tafenoquine (TQ) and Primaquine (PQ) When Either Are Taken Together With Chloroquine (CQ) for the Treatment of P. Vivax Malaria in Indian Participants Aged 2 Years and Older

Inclusion Criteria:

1. Males and females >=2 years of age and under (<) 65 years of age, weighing >10 kg.

2. The participant has a positive malarial smear for P. vivax with a parasite densityof >100/microliter and <100,000/microliter.

3. The participant has a screening Hb value >8 g/dL.

4. The participant has an axillary temperature of 37.5°C or history of fever 48 hoursbefore recruitment.

5. The participant has a G6PD value (measured using the SD Biosensor STANDARDTM G6PDtest) 6.1 units/gram (U/g) Hb for G6PD activity (6.1 U/g Hb cut-off is applicablefor both males and females).

6. A female participant is eligible to participate if she is not pregnant orbreastfeeding, and if one of the following conditions applies:

• Is a woman of non-childbearing potential (WONCBP) as defined in

• Is a Women of Childbearing Potential (WOCBP) and using a contraceptive methodthat is highly effective (with a failure rate of <1% per year), with low userdependency, during the study intervention period and for at least 90 days afterthe last dose of study intervention. The investigator should evaluate thepotential for contraceptive method failure (e.g., noncompliance, recentlyinitiated) in relationship to the first dose of study intervention. Theinvestigator is responsible for review of medical history, menstrual history,and recent sexual activity to decrease the risk for inclusion of a woman withan early undetected pregnancy.

7. A WOCBP must test negative on a highly sensitive pregnancy test (urine or serum asrequired by local regulations) before the first dose of study intervention.

8. The participant is willing and able to comply with the procedures described in thestudy protocol. The participant or parent/legal guardian, as applicable, has givenwritten informed, dated consent; and the participant has given written assent, ifapplicable, to participate in the study.

Exclusion Criteria:

1. The participant has severe P. vivax malaria as defined by WHO criteria [WHO, 2023].

2. The participant has a mixed malaria infection (identified by a malarial smear).

3. The participant has a condition that may affect absorption of study medication, suchas severe vomiting (no food or inability to take food during the previous 8 hours).

4. The participant has a history of porphyria, psoriasis, or epilepsy.

5. The participant has a history of allergy, intolerance to or a known contraindicationto the use of mefloquine (or other aryl amino alcohol drugs), chloroquine,tafenoquine, primaquine, any other 4- or 8-AQ or any of their respective excipients.

6. The participant has received treatment with any investigational drug within 30 daysof study entry, or within 5 half-lives, whichever is longer.

7. The participant has previously enrolled in this study.

8. The participant has a recent history of illicit drug abuse or heavy alcohol intakethat in the opinion of the investigator could compromise full participation in thestudy or adherence to study procedures.

9. Participants with a current or past history of serious psychiatric disorders.

10. The participant has a clinically significant concurrent illness (e.g., pneumonia,tuberculosis, meningitis, septicemia, dengue, coagulopathy, severe hemorrhage, orfebrile convulsions prior to consent) or a pre-existing condition (e.g., renaldisease, malignancy, or severe malnutrition according to WHO child growth standards)or systemic disease predisposing patients to suffer from granulocytopenia, such asrheumatoid arthritis and lupus erythematosus or severe ocular disease.

11. The participant is known to be HIV-infected and/or is currently on antiretroviraltherapy.

12. The participant is regularly using drugs with hemolytic potential.

13. The participant has a QT corrected by Fridericia's formula (QTcF) >450 msec,evidence of bradycardia (<50 beats per min) or ventricular arrhythmias on thescreening ECG, a history of cardiac disease (e.g., myocardial infarction, congenitalheart disease, or arrhythmia), hypokalemia (<2.9 millimoles per liter [mmol/L]) orhyperkalemia (>=6.0 mmol/L) at Screening.

14. The participant has taken drugs with antimalarial activity (e.g., artemisinin-basedcombination therapies, mefloquine, primaquine, chloroquine, tafenoquine or any other 4-AQ) within 30 days prior to study entry.

15. The participant has taken or will likely require during the study the use of:

16. Histamine-2 blockers (restricted to first 3 days whilst receiving CQ)

17. Antacids (restricted to first 3 days whilst receiving CQ)

18. Drugs of the biguanide class (i.e., phenformin, metformin, buformin)

19. Anti-arrhythmic agents (i.e., dofetilide, procainamide, pilsicainide)

20. Medications that prolong the QTc interval

21. The participant has liver transaminases (ALT/AST) >2 times the upper limit of normal (ULN).