Repeated ALX-0681 administration reversibly decreases the FVIII:C and VWF:Ag concentrations. FVIII:C (%; A) and VWF:Ag (B) were measured in baboon plasma of the control (●; n = 4), preventive (□; n = 4), and therapeutic (; n = 4) animals as a function of time (days). Results were analyzed with a mixed model and a posthoc test with Tukey multiple comparison adjustment. Data are represented as means ± SD. “a” indicates a significant difference between control and preventive animals (P < .001); “b,” a significant difference between control and therapeutic animals (P < .001).