131-Iodine Tositumomab in lymphoma

Abstract

Radioimmunoconjugates are radioisotope-bound monoclonal antibodies that target radiation specifically to sites of lymphoma involvement. Initial studies of 131I-tositumomab in non-Hodgkin’s lymphoma (NHL) have suggested benefit in patients with relapsed or refractory indolent disease. However, the routine adoption of this agent is tempered by concerns of associated toxicities and unclear long-term benefit. A comprehensive search for studies on 131I-tositumomab use in lymphoma was completed. The aims of this systematic review were to summarize and evaluate the evidence on: (1) the benefits and risks of this novel therapy; (2) predictors for response and toxicity; and (3) the role of dosimetry and imaging studies prior to treatment. A total of 18 trials investigating the use of 131I-tositumomab for the treatment of adult patients with NHL were identified. In trials of patients with relapsed or refractory indolent NHL, overall response rates ranged from 67%-83%. In patients with follicular NHL refractory to the monoclonal antibody rituximab response rates remained high (65-72%). However, in rituximab-naïve patients with relapsed or refractory indolent or transformed NHL, improvements in time-to-progression or survival have not clearly been established. 131I-tositumomab is an active agent in relapsed and refractory non-Hodgkin’s lymphoma that should be considered in select patients.