A Randomized Phase III Trial of ICE Chemotherapy With or Without Rituximab for the Treatment of Relapsed or Refractory CD20 Expressing Agressive B-Cell Non-Hodgkin's Lymphomas in Patients Not Suitable for High Dose Therapy and PBSCT.

First relapse or primary refractory, aggressive large B-cell Non-Hodgkin's lymphoma; failed prior combination chemotherapy with an anthracycline containing regimen; REAL or WHO classification of diffuse large B cell lymphoma; small non-cleaved cell Burkitt's-like ARE eligible; lymphoblastic lymphoma or mantle cell lymphoma are NOT eligible; patients must not be suitable for or must have refused treatment with salvage chemo followed by high dose therapy and autologous stem cell rescue in the opinion of the investigator; B-cell lymphomas must express the CD20 antigen; measurable disease; bone marrow aspirate and biopsy; CT of chest, abdomen, pelvis; no central nervous system involvement by lymphoma; serum bilirubin =< 2.0 x IULN; serum creatinine = < 1.5mg/dl or estimated creatinine clearance > 60 ml/min; LDH; age 3 18 years; no known HIV.