A Phase 2 interventional study of SJ733/TQ placebo and CQ/TQ Placebo in Malaria, Malaria Vivax and Radical Cure, sponsored by R. Kiplin Guy. Not yet recruiting at 1 site in Peru. Open to participants aged 18 Years to 76 Years. Per ClinicalTrials.gov, last updated 2026-10-21.
Sponsored by R. Kiplin Guy · Phase 2, Interventional, and Treatment
The goal of this Phase 2b study is to examine the safety and efficacy of the combination of SJ733, an investigational agent, and tafenoquine for the radical cure of uncomplicated P. vivax malaria monoinfection in adult participants and determine the contributions of SJ733 to the effect. SJ733 will be administered in a 1-, 2-, or 3-day treatment schedule in combination with a single dose of tafenoquine.
SJ733-2002 study is a blinded, randomized, placebo- and active comparator-controlled study to examine the safety and efficacy of combining 1, 2, or 3 sequential daily doses of SJ733 with a single dose of TQ given on Day 1 for the radical cure of uncomplicated P. vivax malaria. This study will also establish the role of SJ733 in driving blood stage and liver stage parasite killing and any pharmacological interactions with Tafenoquine (TQ). Hence, this study includes placebo controlled SJ733 and Chloroquine (CQ) monotherapy arms. The six arms in this study will be run simultaneously and participants randomized with a 1:1:1:1:1:1 ratio until all arms are filled. All participants will be monitored for 180 days, with parasitemia endpoints measured on Days 7, 14, 21, 28, 35, 42, 60, 120, and 180 to provide maximum comparability to historical studies. At all times during these studies any participants that develop symptomatic disease or detectable parasitemia will be rescued with local standard-of-care (according to national guidelines). Any participant who does not relapse during the study will be treated following the last day of the study with the same rescue therapy.
123 studies on the registry are indexed under Malaria, Vivax; 19 are open to participants now.
This study's planned enrollment of 104 is below the median of 150 across 103 interventional studies indexed under Malaria, Vivax.
Browse Malaria, Vivax studies →R. Kiplin Guy is the lead sponsor of 2 studies on the registry; 1 is open to participants now.
Compared within Malaria, Vivax, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Malaria. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
A female participant meets eligibility in this study if she is non-pregnant, non-lactating and if she is of: non- defined as: (12 months of spontaneous amenorrhea or \<6 months of spontaneous amenorrhea with serum FSH >40 mIU/mL), pre-menopausal and has had a hysterectomy, a bilateral oophorectomy (removal of the ovaries), or a bilateral tubal ligation with medical report verification, negative pregnancy test or, child-bearing potential, with 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 75 days after stopping study treatment:
i. Use of oral, implantable, or injectable hormonal , either combined or progestogen alone, used in conjunction with barrier method (condom or diaphragm).
ii. Use of an intrauterine device with a documented failure rate of \<1% per year.
iii. Double barrier method consisting of condom and diaphragm. iv. Male partner who is sterile prior to the female participant's entry into the study and is the sole sexual partner for that female.
v. Complete abstinence from intercourse throughout the study and for a period of 75 days after stopping study treatment.
A male participant meets eligibility in this study if he meets one of the following conditions:
Exclusion Criteria:
alterations to hematologic or clinical chemistry parameters that in the opinion of the investigator precludes participation in the study, including:
i. Potassium[hypokalemia] ii. Magnesium [hypomagnesemia] e. level \< 9 g/dL f. level \< 50,000/mm3
Clinically significant alterations to cardiac function
Received any antimalarial treatment (alone or in combination) in the past containing:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
SJ733 (600 mg) once a day for 3 consecutive days combined with tafenoquine placebo on the first day
Drug: SJ733/TQ placebo
Chloroquine (600 mg) for 2 consecutive days then Chloroquine (300 mg) for 1 day, combined with tafenoquine placebo on the first day
Drug: CQ/TQ Placebo
Chloroquine (600 mg) for 2 consecutive days then Chloroquine (300 mg) for 1 day, combined with tafenoquine (300 mg) once on the first day
Drug: CQ/TQ
SJ733 (600 mg) once a day for 3 consecutive days combined with tafenoquine (300 mg) once on the first day
Drug: SJ733 (3-day)/TQ
SJ733 (600 mg) once a day for 2 consecutive days, followed by SJ733 placebo for 1 day, combined with tafenoquine (300 mg) once on the first day
Drug: SJ733 (2-day ) /TQ
SJ733 (600 mg) once, followed by SJ733 placebo for 2 days, combined with tafenoquine (300 mg) once on the first day
Drug: SJ733(1-day)/TQ
SJ733 combined with Tafenoquine Placebo
Also known as: SJ733, Tafenoquine Placebo
Chloroquine combined with Tafenoquine Placebo
Also known as: Chloroquine, Tafenoquine Placebo
Drug page: Chloroquine
Chloroquine combined with Tafenoquine
Also known as: Chloroquine, Tafenoquine
Drug page: SJ733
SJ733 (3-day schedule) combined with Tafenoquine
Also known as: SJ733, Tafenoquine
Drug page: SJ733
SJ733 (2-day schedule) combined with Tafenoquine
Also known as: SJ733, Tafenoquine
Drug page: SJ733
SJ733 (1 day schedule) combined with Tafenoquine
Also known as: SJ733, Tafenoquine
Parasitological Recurrence Free survival (RFS)
Recurrence free survival (RFS), defined as non-relapses of P. vivax at 180 days given parasitemia clearance at 14 days.
Time frame: 14 - 180 days for each arm
Clinical Recurrence Free Survival
Absence of malaria-related clinical signs or symptoms over 180 days following confirmed parasitemia clearance at Day 14.
Time frame: 14 to 180 days for each arm
Percentage of patients with treatment related adverse events
Incidence, severity, drug-relatedness, and seriousness of adverse events
Time frame: 1 to 180 days for each arm
Percent of patients with clinically significant abnormal vital signs
Number of and seriousness of with clinically significant abnormal vital signs including changes from baseline
Time frame: 1 to 180 days for each arm
Percent of patients with a decrease in hemoglobin (HB) > 2 g/dL from baseline to an absolute value of <7 g/dL
Proportion of participants with a decrease in hemoglobin (Hb): \> 2 g/dL from baseline to an absolute value of \< 7 g/dL
Time frame: 1 to 180 days for each arm
Percent of patients with an Absolute Neutrophil Count < 1000/μL after baseline
Proportion of participants with an absolute neutrophil count \< 1,000/μL after baseline
Time frame: 1 to 180 days for each arm
Percent of patients with significant changes in ECG findings
Proportion of participants with significant changes in ECG findings, including heart rate, ECG intervals (PR, QTcB, QTcF), conduction changes or abnormalities
Time frame: 1 to 180 days for each arm
Percent of patients with clinically significant increases in venous methemoglobin levels
Proportion of participants with clinically significant increases in venous methemoglobin levels
Time frame: 1 to 180 days for each arm
Number of participants with signs and symptoms of uncomplicated P. vivax malaria infection
Proportion of participants with symptoms or physical examination signs related to uncomplicated P. vivax malaria (e.g., headache, nausea, fatigue, fever auxiliary temperature, \>/= 37.5 C, chills/shivering/rigors, prostration, conjunctival jaundice, and respiratory distress)
Time frame: 180 days for each arm
Parasite clearance Time
Parasite Clearance Kinetics in participants with P. vivax malaria infection as measured by Microscopy
Time frame: 72 hours for each arm
Area Under the Plasma Concentration Time Curve (AUC)
AUC of SJ733, its primary metabolite, SJ506, and tafenoquine
Time frame: 180 days
Maximum Plasma Concentration (Cmax)
Cmax of SJ733, its primary metabolite, SJ506, and tafenoquine
Time frame: 180 days
Correlation between microscopy and PCR measures of parasite clearance kinetics / efficacy
Effect of the proposed three-day therapy on PCR adjusted parasitological outcomes, complementing microscopy-based assessments, in participants with P. vivax malaria
Time frame: 180 days for each arm
Plan to share: No
Start is estimated for Dec 2026; primary completion for Nov 2028, 23 months later.
Start moved once since we started tracking on Sep 25, 2026: Oct 2026 → Dec 2026, on Oct 21, 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: SJ733
R. Kiplin Guy