FIG 2.

In vivo exposure-response relationship between the PK parameter 24-h AUC/MIC and treatment effect for 12 K. pneumoniae strains (A) and 5 P. aeruginosa strains (B) in the neutropenic murine lung infection model. Each symbol is the mean of three lung infection replicates. Eight total drug dosing regimens were fractionated into an every-6-h regimen. The delafloxacin exposure is represented on the x axis as plasma 24-h AUC/MIC. The burden of organisms was measured at the start and end of therapy over a 24-h period. Horizontal dashed line at 0, burden of organisms at the start of therapy. Data points above the line, net growth (i.e., increase) in burden; data points below the line, net reduction in bacterial burden. Line drawn through the data, best-fit line based on the sigmoid E_max model (Hill equation). Additional PD paremeters shown are E_max, 50% maximal effect point (ED₅₀), slope of the line (N), and R² (coefficient of determination).