Study to Assess the Incidence of Hemolysis, Safety, and Efficacy of Tafenoquine (SB-252263, WR238605) Versus Primaquine in Subjects With Plasmodium Vivax Malaria

Inclusion Criteria

• A female is eligible to enter and participate in the study if she is non-pregnant, nonlactating and if she is of: a. Non-childbearing potential defined as: post-menopausal (12 months of spontaneous amenorrhea or 40 milli-International units per milliliter [mIU/mL]), or pre-menopausal and has had a hysterectomy or a bilateral oophorectomy (removal of the ovaries) or a bilateral tubal ligation, negative pregnancy test or, b. Child-bearing potential, has a negative 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 medication: 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 = 40 percent of the site median value for G6PD normal males. Male subjects must have an enzyme level >= 70 percent of the site median value for G6PD normal males.
• The subject has a screening hemoglobin (Hb) value as follows: Any subject with a G6PD value >=70 percent of the site median value must have a screening Hb value >=7 g/dL; Female subjects with a G6PD value is >=40 - =8 g/dL.
• The subject has a QT duration corrected for heart rate by Fridericia's Formula (QTcF) 100 and 2 x upper limit of normal (ULN).
• The subject has severe vomiting (no food or inability to take food during the previous 8 hours).
• The subject has a clinically significant concurrent illness (e.g., pneumonia, septicemia), pre-existing condition (e.g., renal disease, malignancy), condition that may affect absorption of study medication (e.g., vomiting, severe diarrhea), or clinical signs and symptoms of severe cardiovascular disease (e.g., uncontrolled congestive heart failure, severe coronary artery disease).
• The subject has a history of porphyria, psoriasis, or epilepsy.
• The subject has a history of significant ocular disease (e.g. surgery to the globe, glaucoma, diabetic retinopathy) or has evidence of corneal or retinal abnormalities identified in the clinical screening ophthalmologic examination.
• The subject has taken anti-malarials (e.g., artemisinin-based combination therapies, mefloquine, primaquine, or any other 4- or 8-aminoquinoline) within 30 days prior to study entry.
• The subject has taken or will likely require during the study the use of medications from the following classes: Histamine-2 blockers and antacids; Drugs with hemolytic potential; Drugs known to prolong the QTcF interval; The biguanides phenformin and buformin (but excluding metformin); Drugs that are substrates of the renal transporters OCT2, MATE1 AND MATE-2K and have a narrow therapeutic index (for example, the anti-arrhythmic agents dofetilide, procainamide and pilsicainide)
• The subject has received treatment with any investigational drug within 30 days of study entry, or within 5 half-lives, whichever is longer.
• The subject has a recent history of illicit drug abuse or heavy alcohol intake, such that full participation in the study could be compromised.