Mean (95% CI) free C5 levels in the ravulizumab and eculizumab groups over time. (A-B) A gyros-based fluorescence assay was used for patients who received ravulizumab (A), and an electrochemiluminescence immunoassay was used for patients who received eculizumab (B). Baseline (BL) is defined as the last nonmissing value before first dose of study drug. Day 29, 43, 57, 85, 99, 113, 141, 155, and 169 data are from anytime for the ravulizumab group and predose for the eculizumab group. Horizontal line indicates free C5 level of 0.5 µg/mL. Free C5 levels <0.5 µg/mL are associated with complete inhibition of C5 activity.