Statistical analysis
Efficacy was evaluated in all randomly assigned patients in Asia and safety was evaluated in all randomly assigned patients in Asia who received ≥1 dose of study treatment. OS, PFS and DOR were estimated using the nonparametric Kaplan–Meier method and rules for censoring, and between-arm differences in OS and PFS were assessed using a log-rank test. A Cox proportional hazards model with the Efron method of handling ties was used to estimate hazard ratios (HRs) and associated 95% confidence intervals (CIs). Statistical comparisons for efficacy were not performed. The data cut-off date for this analysis was 26 March 2019.