Toxicity of High-Dose Sequential Chemotherapy and Purged Autologous Hematopoietic Cell Transplantation Precludes Its Use in Refractory/Recurrent Non-Hodgkin's Lymphoma

We conducted a pilot study in 20 patients with high-risk or recurrent/refractory non-Hodgkin's lymphoma (NHL) using high-dose sequential chemotherapy (HDSC) and autologous hematopoietic cell transplantation (AHCT). After cytoreduction with standard salvage therapy, HDSC/AHCT was administered in 4 phases at 2- to 4-week intervals. Phase 1 consisted of cyclophosphamide 7 g/m² followed by granulocyte colony-stimulating factor (G-CSF) at 10 μg/kg per day and leukapheresis upon recovery from white blood cell nadir. The hematopoietic cell product was enriched by Percoll gradient separation and purged with a B-cell or T-cell monoclonal antibody panel and complement. Phase 2 consisted of methotrexate 8 g/m² with leucovorin rescue and vincristine 1.4 mg/m². Phase 3 was etoposide 2 g/m² with G-CSF 5 μg/kg per day. In phase 4, the preparative regimen of mitoxantrone 60 mg/m² and melphalan 180 mg/m² was administered followed by AHCT. The NHL histologies were diffuse large cell, follicular/diffuse mixed, small noncleaved cell, T-cell-rich B-cell, lymphoblastic, and peripheral T cell. The remission status was first partial remission (PR1; n = 1) or beyond first complete remission (post-CR1; n = 19). Of the 20 patients enrolled, 11 proceeded through all 4 phases. Nine were removed from the study after the first or second phase because of progressive disease (n = 5), poor hematopoietic cell mobilization (n = 1), excessive toxicity (n = 2), and chronic active hepatitis C (n = 1). Treatment-related toxicities in the remaining 11 transplant recipients were cardiomyopathy, hemorrhagic cystitis, persistent cytopenias, acute renal failure, abnormal liver function test results, and infectious complications. There were no treatment-related deaths. Eight of the 11 transplant recipients were alive, 6 without disease, at a median follow-up of 2.7 years. The estimated median 2-year event-free survival was 55%, and overall survival was 70%. We conclude that HDSC/AHCT in refractory/recurrent NHL is associated with considerable acute and chronic toxicities. Given the toxicity profile, efficacy data were not sufficiently promising to warrant further study.