 - Patients with a currently active second malignancy, other than non-melanoma skin cancers are not eligible. This includes Waldenstroms Macroglobulinemia, since such patents have experienced transient increases in IgM following initiation of rituximab, with the potential for hyperviscosity syndrome requiring plasmapheresis. Patients are not considered to have a currently active malignancy if they have completed anti-cancer therapy, and are considered by their physician to be at less than 30 risk of relapse. 