¹³¹I–Tositumomab in Lymphoma

Radioimmunoconjugates are radioisotope-bound monoclonal antibodies that target radiation specifically to sites of lymphoma involvement. Initial studies of ¹³¹I–tositumomab in non-Hodgkin lymphoma (nhl) have suggested benefit in patients with relapsed or refractory indolent disease. However, the routine adoption of this agent is tempered by concerns about associated toxicities and unclear long-term benefit. Based on a comprehensive search for studies on ¹³¹I–tositumomab use in lymphoma, this systematic review summarizes and evaluates the evidence on (1) the benefits and risks of this novel therapy, (2) the predictors for response and toxicity, and (3) the role of dosimetry and imaging studies before treatment. We identified 18 trials investigating the use of ¹³¹I–tositumomab for the treatment of adult patients with nhl. In trials of patients with relapsed or refractory indolent nhl, overall response rates ranged from 67% to 83%. In patients with follicular nhl refractory to the monoclonal antibody rituximab, response rates remained high (65%–72%). However, in rituximabnaïve patients with relapsed or refractory indolent or transformed nhl, improvements in time to progression or survival have not been clearly established. ¹³¹I–Tositumomab is an active agent in relapsed and refractory non-Hodgkin lymphoma that should be considered in selected patients.