This is a phase I, open label, randomized study to determine any drug interaction between Pyramax (pyronaridine/artesunate) and the protease inhibitor ritonavir in healthy volunteers. A total of 34 healthy volunteers (17 per treatment arm) will be enrolled in the study so that at least 30 (15 per treatment arm) will complete it. Subjects will be randomly assigned in a 1:1 ratio to receive either ritonavir (100 mg) twice daily for 17 days from Day 1-17 plus Pyramax (180:60 mg) once daily for 3 days from Day 8-10 in Arm A or pyronaridine/artesunate (180:60 mg) alone once daily for 3 days from Day 1-3 in Arm B.~Subjects will come to the clinic the evening before first dosing of Pyramax / ritonavir. If enrolled, and according to the treatment arm, subjects will stay in the clinic and attend subsequent visits as follows:~Arm A:~Inpatient day -1 (evening) to day 17~Ambulatory clinic visit once daily (morning) on day 22, 29, 36, 43 and 50 (end of study visit)~Arm B:~Inpatient day -1 (evening) to day 4 (morning),~Ambulatory clinic visit once daily (morning) on Day 5, 6, 8, 15, 22, 29, 36, and 43.(end of study visit) The subjects will be evaluated for pharmacokinetic parameters and safety/tolerability.
The primary objective of the study is to determine any drug interaction between the antimalarial Pyramax (pyronaridine artesunate) and the protease inhibitor ritonavir in healthy subjects. The secondary objective of the study is to assess further the safety of Pyramax in this setting.