Statistical analysis
REGRESSION, EVENTS, EVENT
Sample-size calculations for the RCP have been described previously [A mixed model for repeated measures (MMRM) was used to analyze changes from baseline, with the assumption that missing data were missing at random. Missing data were not imputed. Data are shown as least-squares (LS) mean change from baseline with 95% confidence intervals (CIs). The estimates for the RCP were based on an MMRM that included treatment group, stratification factor region, baseline score, study visit, and study visit by treatment group interaction. Visits up to Week 26 were included in the model. The OLE estimates were based on an MMRM that included stratification factor region, baseline score, and study visit. A model was fit for the ravulizumab–ravulizumab and placebo–ravulizumab arms of the OLE analysis set separately.The responder analysis calculated the proportion of patients who achieved a clinical response from the RCP baseline in patients who initiated ravulizumab in the RCP and from the OLE baseline in patients who initiated ravulizumab in the OLE.A generalized estimating equation Poisson regression repeated measures model was used to analyze clinical deterioration event rates, with the number of events as the dependent variable, the logarithm of patient-years as the offset variable, and the study phase indicator (pre-study, placebo, or ravulizumab) as the explanatory factor.The present interim analysis was prespecified. Data cut-off was 9 November 2021, including data for up to 60 weeks from the RCP baseline (34 weeks from the OLE baseline when patients receiving placebo during the RCP switched to ravulizumab). All analyses were performed using Statistical Analysis Software Version 9.4 (SAS