Efficacy and Safety Study of Tafenoquine (TQ) Co-administered With Dihydroartemisinin-piperaquine (DHA-PQP) for the Radical Cure of Plasmodium Vivax (P. Vivax) Malaria

Tafenoquine (TQ) is an 8-aminoquinoline anti-malarial drug which is in development as a single-dose treatment for the radical cure of P.vivax malaria when given with standard doses of chloroquine. Currently, the only available drug for radical cure is primaquine (PQ) which requires administration over 14 days, resulting in poor compliance. In Indonesia, chloroquine has been replaced by artemisinin-based combination therapy (i.e. ACTs) due to widespread chloroquine resistance. This study will evaluate the efficacy and safety of a single dose of tafenoquine when co-administered with an ACT (i.e. DHA-PQP). This single-center, double-blind, double-dummy, randomized study will test the superiority of DHA-PQP plus TQ against DHA-PQP alone in the prevention of P. vivax malaria relapse at 6 months. The study will be conducted in male Indonesian soldiers diagnosed with P.vivax malaria on return from deployment to a malarious region of Indonesia. A PQ plus DHA-PQP comparator arm is included to provide an informal comparison against the standard 14 day treatment for P.vivax malaria in Indonesia. Subjects who are glucose-6-phosphate dehydrogenase deficient (G6PD deficient) will be excluded due to the risk of acute hemolysis following dosing with 8-aminoquinolines drugs. Subjects who have a recurrence of P.vivax malaria during the study will be treated with an ACT plus PQ (0.5mg/kg for 14 days), in line with local treatment guidelines. At the end of the 6 month follow up period, any subject who has not relapsed will be given open label PQ (0.5mg/kg daily for 14 days) to minimize the likelihood of relapse after the study. Approximately 200 subjects will be screened to achieve 150 randomized subjects. The total duration of study for each subject will be 180-195 days. This study is being carried out to support registration of TQ in Indonesia and other countries where ACTs are first line therapy.