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

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).

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.

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.

(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.