TABLE 1.

Effect of maribavir on EC₅₀s of other anti-CMV drugs

Cell type and strain	UL97 genotype	Drug A	Drug B (concn [μM])	EC50 (μM) of drug A (no. of replicates)a	FIC	MBV ∑FICb
HFF
T2233	WTc	GCV	None	1.0 ± 0.4 (28)
		GCV	MBV (0.04)	1.6 ± .76 (13)	1.5	>3.9
		GCV	MBV (0.16)	4.5 ± 1.2 (19)	4.3	>6.7
		GCV	MBV (0.64)	6.6 ± 3.3 (17)	6.3	>8.7
		GCV	MBV (2.5)	8.3 ± 2.3 (12)	8.0	>10
		GCV	MBV (5)	14 ± 4.5 (15)	13	>15
		GCV	MBV (10)	13 ± 3.0 (7)	13	>15
		FOS	None	45 ± 8.3 (15)
		FOS	MBV (10)	39 ± 7 (8)	0.9	0.9
		CDV	None	0.26 ± 0.07 (14)
		CDV	MBV (10)	0.27 ± .18 (7)	1.0	1.1
		MBV	None	13 ± 3.6 (16)
		MBV	GCV (1)	>32 (6)	>2.4
		MBV	FOS (40)	0.47 ± 0.3 (16)	0.04
		MBV	CDV (0.3)	0.41 ± 0.05 (5)	0.03
HEL cells
T2233	WT	GCV	None	0.55 ± 0.18 (12)
		GCV	MBV (0.04)	1.2 ± 0.19 (6)	2.2	4.1
		GCV	MBV (0.16)	2.6 ± 0.89 (13)	4.7	6.6
		GCV	MBV (0.32)	4.9 ± 1.0 (11)	8.9	11
		FOS	None	39 ± 10 (7)
		FOS	MBV (0.16)	27 ± 9 (7)	0.7	1.6
		CDV	None	0.36 ± 0.04 (6)
		CDV	MBV (0.16)	0.29 ± 0.12 (6)	0.8	1.6
		MBV	None	0.10 ± 0.03 (51)
		MBV	GCV (0.5)	0.19 ± 0.01 (4)	1.9
		MBV	FOS (40)	0.09 ± 0.03 (7)	0.9
		MBV	CDV (0.4)	0.08 ± 0.00 (4)	0.8
T2264	L397R (MBVr)	MBV	None	24 ± 9.1 (7)
		GCV	None	1.9 ± 0.73 (6)
		GCV	MBV (10)	1.9 ± 0.74 (4)	1.0
		FOS	None	31 ± 14 (7)
		FOS	MBV (10)	48 ± 13 (4)	1.6
		CDV	None	0.47 ± 0.09 (4)
		CDV	MBV (10)	0.45 ± 0.3 (6)	1.0
T2258	C592G (low-grade GCVr)	MBV	None	0.2 ± 0.04 (5)
		GCV	None	2.5 ± 1.4 (5)
		GCV	MBV (0.2)	7.2 ± 1.1 (4)	2.9
T2260	L595S (GCVr)	MBV	None	0.25 ± 0.08 (5)
		GCV	None	7.9 ± 3.2 (5)
		GCV	MBV (0.2)	8.6 ± 5.4 (7)	1.1

^aEC₅₀s are for drug A in the presence of drug B and are shown as the mean±the standard deviation.

^bValues of >4, defining drug antagonisms, are in bold.

^cThe phenotype associated with the genotype is in parentheses.