Time-to-event analysis highlights the durability of anti-IL6–directed therapies. (A) Survival curve showing time to event by regimen category. Event is defined as disease progression or start of new regimen. (B) Results from a Cox proportional hazards model comparing siltuximab w/wo corticosteroids, tocilizumab w/wo corticosteroids, rituximab w/wo corticosteroids, and chemotherapy-based regimens, stratified by severity and controlled for age, sex, and clinical subtype. Siltuximab w/wo corticosteroids demonstrated stronger durability over rituximab w/wo corticosteroids (hazard ratio, 2.72; 95% CI, 1.50-4.91; P = .001).