(a) Plasma levels of scFv(FRP5)-ETA at steady state. Plasma samples were taken from individual patients at each dose level at the indicated time points before and after infusion of scFv(FRP5)-ETA on treatment day 5. Plasma concentrations were determined by capture ELISA with 1:10 diluted plasma including standard scFv(FRP5)-ETA concentrations for quantification. No scFv(FRP5)-ETA was detected in the predose levels, indicating that no accumulation occurred with a once-daily dose interval. (b) Area under the concentration–time curve (AUC0–5 hours) at steady state on treatment day 5 for the different dose levels. The area under the concentration–time curve was calculated according to the trapezoidal rule from 0 to 5 hours. In accordance with the concentration-time profiles there was a dose-dependent increase of the area under the concentration–time curve, indicating linear pharmacokinetic behavior in the investigated dose range.