A new review recaps how cold agglutinin disease is driven by clonal B-cell biology and complement-mediated hemolysis, and it places current and emerging therapies in that framework. The paper highlights why steroids and splenectomy have fallen short for many patients, while complement inhibition—led by sutimlimab—has reshaped the standard of care. The review also surveys how additional agents under study could further improve outcomes, including for patient subgroups where response variability remains a clinical challenge. The overall message is that pathway-specific therapy has progressed the field more than broad immunosuppression. For biotech, the cold agglutinin category is a useful reference point for how complement-targeted approaches can translate mechanistic clarity into durable treatment options.