PRIOR CONCURRENT THERAPY: No more than 2 prior regimens allowed Prior tandem transplant considered 2 prior regimens Chemotherapy prior to bone marrow transplantation as part of induction considered 1 prior regimen Retreatment with same regimen (e.g., repeated alkylating agents) considered 1 prior regimen Biologic therapy: No prior anti-CD20 therapy At least 1 month since prior epoetin alfa No concurrent epoetin alfa for 2 months after registration Chemotherapy: At least 28 days since prior alkylating agents At least 28 days since prior purine nucleoside analogues Endocrine therapy: At least 28 days since prior corticosteroid therapy Radiotherapy: At least 4 weeks since prior radiotherapy Surgery: Not specified Other: Concurrent digoxin to control atrial fibrillation allowed