Figure 1.

Combination index (CI) of ITX 5061 in combination with various anti–hepatitis C virus (HCV) compounds. Numerical values above the bars are the mean CI. Error bars represent the standard error of the mean of the CI. The 2 lines at 0.9 and 1.1 represent the bounds of an additive interaction. +, synergy; ±, additivity; −, antagonism. The 50% effective dose (ED₅₀), 75% effective dose (ED₇₅), and 90% effective dose (ED₉₀) refer to the combination index at the 50% effective concentration (EC₅₀), 75% effective concentration (EC₇₅), and 90% effective concentration (EC₉₀), respectively, of each compound.