Study to Assess the Incidence of Hemolysis, Safety, and Efficacy of Tafenoquine (SB-252263, WR238605) versus Primaquine in Subjects with Plasmodium vivax Malaria
Trial overview
Percentage of participants with clinically relevant hemolysis.
Timeframe: Up to Day 180
Percentage of female participants with moderate glucose-6 phosphate dehydrogenase (G6PD) deficiency experiencing clinically relevant hemolysis.
Timeframe: Up to Day 180
Rate of relapse-free efficacy at six months post dose
Timeframe: 6 months post dose
Rate of relapse-free efficacy at four months post dose
Timeframe: 4 months post dose
Time to relapse of P. vivax malaria
Timeframe: Up to Day 180
Time to parasite clearance
Timeframe: Up to Day 180
Time to fever clearance
Timeframe: Up to Day 9
Time to gametocyte clearance
Timeframe: Up to Day 180
Number of participants with recrudescence
Timeframe: Up to Day 32
Number of participants with genetically homologous and genetically heterologous P. vivax infections
Timeframe: Up to Day 180
Number of participants with clinical chemistry laboratory data outside the reference range
Timeframe: Up to Day 120
Number of participants with hematology laboratory data outside the reference range
Timeframe: Up to Day 120
Number of participants with abnormal urinalysis dipstick results
Timeframe: Up to Day 120
Number of participants with treatment emergent adverse events (TEAEs) and serious TEAEs
Timeframe: Up to Day 180
Number of participants with electrocardiogram (ECG) findings
Timeframe: Up to Day 29
Change from Baseline in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP)
Timeframe: Baseline and up to Day 180
Change from Baseline in pulse rate
Timeframe: Baseline and up to Day 180
Change from Baseline in temperature
Timeframe: Baseline and up to Day 180
Number of participants with P. falciparum
Timeframe: Up to Day 180
Number of participants with keratopathy
Timeframe: Up to Day 180
Number of participants with change in Best Corrected Visual Acuity Test Scores
Timeframe: Baseline and up to Day 180
Number of participants with retinal changes from Baseline
Timeframe: Baseline and up to Day 180
Change from Baseline in percent methemoglobin
Timeframe: Baseline and up to Day 120
Cost associated with relapse episode of P vivax malaria
Timeframe: Up to Day 180
Cost associated with a hemolysis event
Timeframe: Up to Day 180
Cost incurred with purchase of medications associated with relapse episode of P. vivax malaria
Timeframe: Up to Day 180
Cost incurred with purchase of medications associated with hemolysis event
Timeframe: Up to Day 180
Number of participants or care givers who had taken time off from normal occupation due to relapse episode of malaria
Timeframe: Up to Day 180
Number of participants or care givers who had taken time off from normal occupation due to a hemolysis event
Timeframe: Up to Day 180
Number of participants with action taken to treat relapse episode of P. vivax malaria
Timeframe: Up to Day 180
Number of participants with action taken to treat a hemolysis event
Timeframe: Up to Day 180
Oral clearance (CL/F) of TQ
Timeframe: Day 2, Day 3, Day 8, Day 15, Day 29, Day 60 and Day 180
Volume of distribution (Vc/F) of TQ
Timeframe: Day 2, Day 3, Day 8, Day 15, Day 29, Day 60 and Day 180
- 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 <6 months of spontaneous amenorrhea with serum follicle-stimulating hormone >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 <1% per year; Use of depo provera injection; Double barrier method consisting of spermicide with either condom or diaphragm; Male partner who is sterile prior to the female subject’s entry into the study and is the sole sexual partner for that female. Complete abstinence from intercourse for 2 weeks prior to administration of study medication, throughout the study and for a period of 90 days after stopping study medication.
 - The subject has a glucose 6-phosphate dehydrogenase (G6PD) value (measured by a quantitative spectrophotometric phenotype assay) as follows: Female subjects must have an enzyme level >= 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 mixed malaria infection (identified by a malarial smear or rapid diagnostic test).
 - The subject has severe P. vivax malaria as defined by World Health Organization (WHO) 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 <6 months of spontaneous amenorrhea with serum follicle-stimulating hormone >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 <1% per year; Use of depo provera injection; Double barrier method consisting of spermicide with either condom or diaphragm; Male partner who is sterile prior to the female subject’s entry into the study and is the sole sexual partner for that female. Complete abstinence from intercourse for 2 weeks prior to administration of study medication, throughout the study and for a period of 90 days after stopping study medication.
 - The subject has a glucose 6-phosphate dehydrogenase (G6PD) value (measured by a quantitative spectrophotometric phenotype assay) as follows: Female subjects must have an enzyme level >= 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
 - <70 percent of the site median value must have a screening Hb value >=8 g/dL.
 - The subject has a QT duration corrected for heart rate by Fridericia’s Formula (QTcF) <450 milisecond (msec). Reading based on an average of triplicate Electrocardiograms (ECGs) obtained over a brief recording period by machine or manual over-read.
 - The subject has a positive malarial smear for P. vivax .
 - The subject has a parasite density of >100 and <100,000 per microliter (μL).
 - Male or female subject aged 16 years or older (18 years or older in Ethiopia) at the time of signing the informed consent.
 - The subject agrees to G6PD genotyping.
 - The subject is willing and able to comply with the study protocol.
 - The subject or parent/legal guardian, as applicable, has given written informed, dated consent; and the subject has given written assent, if applicable, to participate in the study.
 
- The subject has a mixed malaria infection (identified by a malarial smear or rapid diagnostic test).
 - The subject has severe P. vivax malaria as defined by World Health Organization (WHO) criteria.
 - The subject has a history of allergy to chloroquine, mefloquine, tafenoquine, primaquine, or to any other 4- or 8-aminoquinoline.
 - The subject has a liver alanine aminotransferase (ALT) >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.
 
Trial location(s)
Study documents
If you wish to request for full study report, please contact - [email protected]
Results overview
Results posted on ClinicalTrials.gov
Plain language summaries
Plain language summaries of clinical trial results for Phase 2-4 clinical trials that were initiated on or after January 2022 will be posted by GSK within one year following study completion.