Table 3. Anti-HIV-1 activity of nucleoside analogues in SAMHD1 expressing U937 cells.

Nucleoside analogue	PMA−				PMA+
	EC50 (μM)a [95% CI]b		Fold	pc	EC50 (μM) [95% CI]		Fold	p
	SAMHD1	HD206/7AA			SAMHD1	HD206/7AA
ACV	>200	>200	—	—	0.652 [0.175–1.13]	50.9 [46.1–55.8]	78	<0.0001
GCV	>200	>200	—	—	0.876 [0.823–0.929]	>200	>228	<0.0001
CFB	0.138 [0.021–0.255]	0.108 [0.081–0.135]	1	0.0878†	0.0013 [0.000–0.002]	0.029 [0.022–0.036]	22	0.0010
d4T	0.801 [0.531–1.07]	2.71 [1.90–3.52]	3	0.0013	0.528 [0.317–0.739]	5.82 [5.671–5.969]	11	<0.0001
ddI	23.7 [10.6–36.7]	55.1 [44.2–65.9]	2	0.0018	0.109 [0.030–0.188]	8.79 [7.53–10.1]	81	<0.0001
ABC	17.5 [15.9–19.1]	22.1 [7.12–37.1]	1	0.0590†	0.173 [0.164–0.182]	7.06 [4.72–9.40]	41	<0.0007
NVP	0.112 [0.000–0.223]	0.124 [0.000–0.248]	1	0.6442†	0.097 [0.000–0.195]	0.145 [0.113–0.177]	1	0.1297†
RAL	0.011 [0.002–0.020]	0.012 [0.003–0.021]	1	0.2115†	0.070 [0.013–0.127]	0.075 [0.007–0.143]	1	0.7548†

^aEC₅₀ is the effective concentration of drug that inhibits infection of cells by 50% measured as the percentage of GFP⁺ cells in SAMHD1+ or HD206/7AA+ populations. Values were calculated by non-linear regression for at least two independent experiments.

^b95% confidence interval. Non-ambiguous values were subject to a replicate test.

^cEC₅₀ values for each replicate were used to perform an unpaired two-tailed t-test to determine differences between SAMHD1+ and HD206/7AA+ populations.

^†Difference not statistically significant.