Alemtuzumab PKs by exposure group at day of HSCT. (A) Distribution of estimated alemtuzumab concentration at day of HSCT. Based on the median value (0.77 μg/mL, blue vertical dotted line), patients were divided into the high-exposure (>0.77 μg/mL, red area) or low-exposure (≤0.77 μg/mL, blue area) groups. (B) Alemtuzumab observed concentrations (dots) and model–estimated individual PK predictions (solid lines). Patients of the high-exposure group are represented in red, and patients of the low-exposure group are represented in blue.