Kaplan-Meier analysis of OS. Overall survival was analyzed in patients grouped according to (A) high (>124.2 mg/L) vs low (≤124.2 mg/L) baseline dFLC or (B) high (>59%) vs low (≤59%) percentage decrease in dFLC during cycle 1. Cutoffs based on median baseline dFLC and median percentage dFLC decrease from baseline to the last visit of cycle 1, respectively.