How do you treat refractory cold agglutinin disease?

If the patient has refractory cold agglutinin disease not associated with malignant lymphoproliferative disease, I have used intermediate dose Cytoxan. However, there is recent evidence that inhibition of C1s and thus complement activation by a monoclonal antibody sutimlimab markedly reduces hemolys...

Some options include the following:

1. Bortezomib has about a 32% ORR described in this 2018 study (Blood). The study only gave one cycle of therapy which seems quite short, and in practice, I would consider giving at least 3 before deeming a patient refractory.

2. Different rituximab chemo combinati...