Delayed response to fludarabine in lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia

We retrospectively reviewed time to response and incidence of delayed responses in 13 patients with lymphoplasmacytic lymphoma/Waldenstrom's macroglobulinemia (LPL/WM) treated with fludarabine with or without cyclophosphamide. During follow-up post-treatment, seven delayed responses (54%) were observed, improving the initial overall response rate of 61% to a final response rate of 77%.