BMS-378806 (BMS-806) selectively inhibits the binding of HIV-1 gp120 to the CD4 receptor with EC50 of 0.85-26.5 nM in virus.

CD4-gp120:0.85 nM-26.5 nM(EC50)

BMS-806是一种7-azaindole衍生物，通过与gp120结合干扰HIV表面蛋白gp120与宿主细胞受体CD4的相互作用。该化合物能抑制一系列宏观杀伤型和T细胞亲和型HIV-1株，这些实验室株利用CCR5（M-亲和型）或CXR4（T-亲和型）共受体进入细胞，被分类为B型。BMS-806的水溶性为从晶态形式的170 μg/mL，并且在pH=2.1时的溶解度为1.3 mg/mL，在pH=11时的溶解度为3.3 mg/mL，此溶解性曲线揭示了BMS-806的两性质，并估计质子化形式的pKa值为2.9，而游离碱状态大约为9.6。在ELISA实验中，BMS-806与溶解性CD4竞争结合至gp120的单体形式，IC50约为100 nM。BMS-806特异性针对HIV-1，未观察到对HIV-2、SIV、MuLV、RSV、HCMV、BVDV、VSV和流感病毒在10至30 μM浓度范围内有显著的抑制活性，并且对宿主细胞无明显细胞毒性，CC50值>225 μM。[1] BMS-806直接与gp120以大约1:1的化学计量比结合，绑定亲和力类似于溶解性CD4。通过使用携带化合物选择性抗药性替代或gp120-CD4接触位点突变的HIV-1 gp120变体，确定BMS-806的潜在靶位点位于gp120的CD4结合口袋的特定区域内。[2]

当给予BMS-806时，观察到剂量比例增加的AUC和Cmax。在大鼠、犬和猴子中，药物的血浆水平超过了体外半最大抑制病毒复制所需的浓度。BMS-806的分布体积范围为0.4至0.6 L/kg，表示其除了在血浆中，还有更广泛的分布；然而，对大鼠的大脑水平的检查显示中枢神经系统的渗透极少。[1]在37°C下，BMS-806在人类、大鼠、犬和猴的血液中保持稳定，经过2小时的孵育期。在人类、大鼠、犬和猴中，血液对血浆浓度比分别为1.1、0.77、1.2和0.92 (n=3)，这表明BMS-806在血浆和血细胞之间的分布大致相同。根据微粒体预测，BMS-806的人类清除率为9.2 ml/min/kg（占肝血流的46%）。[3]

Drug susceptibility Assay: In general, host cells are infected with HIV-1 at a multiplicity of infection (MOI) of 0.005 50% tissue culture infective doses (TCID50)/cell followed by incubation in the presence of serially diluted inhibitors for 4 to 7 days. Virus yields are quantitated using an RT assay or a p24 enzyme-linked immunosorbent assay (ELISA) (NEN). The results from at least three experiments are used to calculate the 50% effective concentrations (EC50s). The EC50s of IDV, SQV, RTV, and NFV are compared to that of BMS-806 using Dunnett's test. These comparisons are made separately within each assay system. Dunnett's test is used to reduce the probability of false-positive results when a number of treatments are being compared to a control. Confidence bounds for the fold increases in EC50s observes when the same drug is tested in two different assay systems are computed using Fieller's theorem. The use of this theorem is necessary because ratios of parameters (in this case, EC50s) are known not to follow a standard probability distribution, such as the normal distribution. Numbers within the confidence interval are not significantly different from the observed fold increase at the 95% level.

To determine cytotoxicity, MT-2 cells are incubated in the presence of serially diluted BMS-806 for 6 days and cell viability is quantitated using an XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl-2H-tetrazolium-5-carboxanilide] assay to calculate the 50% cytotoxic concentrations (CC50s). (Only for Reference)