Ph 2B/3 Tafenoquine (TFQ) Study in Prevention of Vivax Relapse

Inclusion Criteria: - Positive Giemsa smear for P. vivax

• Parasite density >100 and 40 mIU/mL), pre-menopausal and has had a hysterectomy or a bilateral oophorectomy (removal of the ovaries) or a bilateral tubal ligation with medical report verification, negative pregnancy test or,
• child-bearing potential, has a negative serum pregnancy test at screening, and agrees to comply with one of the following during the treatment stage of the study and for a period of 90 days after stopping study drug:
• Use of oral contraceptive, either combined or progestogen alone used in conjunction with double barrier method as defined below
• Use of an intrauterine device with a documented failure rate of 450 msec.- Exclusion Criteria: - Mixed malaria infections (e.g. identified by Giemsa-stained smear or rapid diagnostic test)
• Severe vivax malaria as defined by World Health Organisation criteria.
• Severe vomiting (no food or inability to take food during previous 8 hours)
• Screening haemoglobin concentration 90% of the site median value for Glucose 6-Phosphate dehydrogenase normals.

Part 2 - Any subject with enzyme level 2x Upper Limit of Normal

• Any clinically significant concurrent illness (e.g. pneumonia, septicaemia), pre-existing conditions (e.g. renal disease, malignancy), conditions that may affect absorption of study medication (e.g. vomiting or severe diarrhea) or clinical signs and symptoms of severe cardiovascular disease (e.g. uncontrolled congestive heart failure or severe coronary artery disease). These abnormalities may be identified on the screening history and physical or laboratory examination.
• Subject has taken antimalarials (e.g. ACT, mefloquine, primaquine, chloroquine) or drugs with anti-malarial activity within the past 30 days by history.
• History of allergy to chloroquine, mefloquine, tafenoquine, primaquine or to any other 4- or 8-aminoquinolines.
• Any contraindications to chloroquine or primaquine administration including a history of porphyria, psoriasis or epilepsy (please refer to chloroquine and primaquine locally approved prescribing information).
• Subject who has previously received study medication for this protocol (all parts) or has received treatment with any other investigational drug within 30 days or 5 half-lives (whichever is longer) preceding the first dose of study medication.
• History of illicit drug abuse or heavy alcohol intake within 6 months of the study.
• Subjects who have taken or will likely require the use of medications from the prohibited medication list which include the following classes: Histamine-2 blockers and antacids.
• Drugs with haemolytic potential.
• Drugs known to prolong the QTc interval