Evaluation of Weekly Tafenoquine

Study Overview
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Brief Summary
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This study is a phase 2b, placebo controlled, randomized, blinded study of the efficacy of WR 238605, a new primaquine analog, compared to placebo as chemosuppression of P. falciparum malaria in Nyanza Province, western Kenya.

Official Title
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Evaluation of Weekly Tafenoquine (SB 252263 / WR 238605) Compared to Placebo for Chemosuppression of Plasmodium Falciparum in Western Kenya

Conditions
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Malaria

Intervention / Treatment
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* Drug: Tafenoquine
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy subjects (male or female) Age of 18-55 years Residing in one of the study villages of the Nyanza Province for the entire study Exclusion Criteria: Any cardiovascular, liver, neurologic, or renal functional abnormality which in the opinion of the clinical investigators would place the subject at increased risk of an adverse event or confuse the result. Female subjects who were pregnant (Positive serum / plasma -HCG as tested within 48 hours of first drug administration). Use of antimalarial drugs not prescribed by study physicians within 2 weeks of study drug initiation. Clinically significant abnormalities (including but not limited to abnormal hepatic or renal function) as determined by history, physical and routine blood chemistries and complete blood count. Known hypersensitivity to any study drug. Unwilling to remain in area and report for drug administration and blood drawing during the duration of the study. Glucose 6 Phosphate Dehydrogenase (G6PD) deficiency.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Load only<br>Loading with tafenoquine 400 mg base for three days followed by placebo weekly. | Drug: Tafenoquine<br>* Tafenoquine 200mg and 400 mg<br>|
| Experimental: Low weekly dose<br>Loading with tafenoquine 200 mg base for 3 days followed by tafenoquine 200 mg weekly. | Drug: Tafenoquine<br>* Tafenoquine 200mg and 400 mg<br>|
| Experimental: High weekly dose<br>Loading with tafenoquine to 400 mg base for 3 days followed by tafenoquine 400 mg base weekly. | Drug: Tafenoquine<br>* Tafenoquine 200mg and 400 mg<br>|
| Experimental: Placebo<br>Loading with placebo for 3 days followed by placebo once weekly. | Other: Placebo<br>* Placebo<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prophylactic outcome. | Thick blood films were stained with Giemsa stain and malaria parasite counts determined by counting the number of asexual parasites per 200 white blood cells. A blood slide was not considered negative until an examination of 200 oil immersion fields showed no parasites. | 13 Weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prophylactic outcome after 7 weeks | Thick blood films were stained with Giemsa stain and malaria parasite counts determined by counting the number of asexual parasites per 200 white blood cells. A blood slide was not considered negative until an examination of 200 oil immersion fields showed no parasites. | 7 Weeks | 
| Prophylactic outcome after 10 weeks | Thick blood films were stained with Giemsa stain and malaria parasite counts determined by counting the number of asexual parasites per 200 white blood cells. A blood slide was not considered negative until an examination of 200 oil immersion fields showed no parasites. | 10 Weeks |