Pharmacodynamics
At baseline (before the first dose), the mean (SD) serum free C5 concentration was 153.6 (37.0) µg/mL, with a range of 50.4–286.0 µg/mL. Administration of ravulizumab achieved immediate and complete terminal complement inhibition (defined as serum free C5 < 0.5 μg/mL), as observed by the end of the first ravulizumab infusion. Complete inhibition was sustained throughout 26 weeks of treatment in all patients at all time points assessed (Fig. Serum-free C5 concentration box plot across 26 weeks of treatment with ravulizumab. Complete terminal complement inhibition (serum free C5 < 0.5 µg/mL) was sustained throughout 26 weeks of treatment in all patients at all time points. For serum free C5 values that were below the limit of quantification, the lower limit of quantification/2 = 0.00915 μg/mL was utilized. The Y-axis is presented on a log scale. The horizontal line in the middle of each box indicates the median, the diamond indicates the mean, and the top and the bottom borders of the box mark the 75th and 25th percentiles, respectively. The whiskers represent the 1.5 interquartile range of the lower and upper quartiles. Outliers are represented by circles beyond the whiskers. The dashed horizontal line indicates a serum free C5 concentration of 0.5 μg/mL, levels below which indicate complete inhibition. 