Radioimmunotherapy with (131)I-rituximab as consolidation therapy for patients with diffuse large B-cell lymphoma.

PURPOSE: The aim of this study was to assess the clinical activity and toxicity of (131)I-rituximab as consolidation therapy for patients with diffuse large B-cell lymphoma (DLBCL) who were treated with R-CHOP (rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisolone).

METHODS: Patients who had been diagnosed with advanced stage (Ann Arbor III or IV) or bulky stage II DLBCL and achieved complete or partial response after six to eight cycles of R-CHOP were enrolled.

RESULTS: A total of 16 patients were enrolled and treated with a single dose of (131)I-rituximab as consolidation therapy after the completion of six or eight cycles of R-CHOP between December 2005 and June 2011. This trial was terminated before the scheduled enrollment owing to low recruitment. Among the 16 patients who were treated with consolidative (131)I-rituximab, 6 achieved complete response (CR) after three cycles of R-CHOP, and another 9 patients further achieved CR after the completion of six or eight cycles of R-CHOP. During the median follow-up period of 73 months, only four patients (25 %) experienced relapse. Two-year relapse-free survival was 88 %, and 5-year relapse-free survival was 81 %. Grade 3 or 4 treatment-related toxicity occurred in four patients and included neutropenia and thrombocytopenia.

CONCLUSIONS: (131)I-rituximab showed promising efficacy as consolidation treatment for patients with DLBCL. A future randomized phase III study to confirm our results is warranted.