Retreatment with rituximab in 178 patients with relapsed and refractory B-cell lymphomas: a single institution case control study.

The role of rituximab retreatment in relapsed B-cell lymphoma is not well known. We undertook a single center retrospective cohort study to investigate the efficacy of retreatment with rituximab with or without chemotherapy in patients with relapsed and refractory B-cell lymphomas. We only included patients treated first-line and in first progression; 178 patients were included in the study, of whom 29% had diffuse large B-cell lymphoma (DLBCL) and 28% had follicular lymphoma (FL). The overall response rate for the first treatment was 81% and for the second treatment was 66%. The median progression-free survival (PFS) for all patients from diagnosis was 13.2 months and from relapse was 12.5 months (not statistically different). For DLBCL the median PFS from diagnosis was 9.6 months and from relapse was 8.4 months, and for FL the median PFS from diagnosis was 26.4 months and from relapse was 19.2 months (not statistically different). The 5-year overall survival was 57%. In a historical comparison with rituximab-naive patients, rituximab-retreated patients had a shorter time to initial relapse than control patients, but there was no difference between the two groups for PFS from relapse. In conclusion, retreatment with rituximab, with or without chemotherapy, yields a high overall response rate in patients with relapsed and refractory B-cell lymphomas. Relapse occurring after rituximab-containing therapy appears to be more aggressive than that occurring after chemotherapy alone. The outcome of retreatment, in terms of progression-free survival, is similar to that of primary treatment.