TABLE 5.

Predicted probability of treatment failure associated with treating a symptomatic infection with hypothetical triple combination therapy^a

Drug-resistant scenario	Probability of treatment failure (%)
	DHA + PQb	Hypothetical drug characteristics
		PRRLC	Duration of action (wks)
			1	2	3	4	5
DHA resistant (Emax = 0.216), PQ resistant (2 × EC50 = 10.9 ng/ml)	8.1	101	4.19	2.79	2.27	2.29	2.23
		102	1.42	<1.00	<1.00	<1.00	<1.00
		103	<1.00	<1.00	<1.00	<1.00	<1.00
DHA resistant (Emax = 0.216), PQ resistant (3 × EC50 = 16.3 ng/ml)	15.2	101	9.35	5.60	5.31	5.46	5.46
		102	3.65	<1.00	<1.00	<1.00	<1.00
		103	<1.00	<1.00	<1.00	<1.00	<1.00
DHA resistant (Emax = 0.216), PQ resistant (4 × EC50 = 21.7 ng/ml)	23.6	101	15.3	10.7	10.0	9.96	9.94
		102	6.02	<1.00	<1.00	<1.00	<1.00
		103	1.25	<1.00	<1.00	<1.00	<1.00

^aThe hypothetical drug was added to the standard 3-day dose of DHA-PQ (120/960 mg). DHA, dihydroartemisinin; PQ, piperaquine; E_max, maximum parasite killing rate of dihydroartemisinin; EC₅₀, concentration of piperaquine associated with half of maximum parasite killing rate; and PRR_LC, parasite reduction ratio per parasite life cycle (38.8 h).

^bInitial total parasite biomass for symptomatic infection of 10¹⁰ parasites.