131I tositumomab

black triangle (131)I tositumomab is a radiolabelled murine anti-CD20 monoclonal antibody that binds specifically to the CD20 antigen on normal and malignant B lymphocytes. It has antitumour activity as a result of emission of beta particles, and activation of antibody-dependent cellular and complement-mediated cytotoxicity. black triangle (131)I tositumomab monotherapy consistently produced objective response rates of >or=60% in patients with relapsed or refractory, low grade or transformed low grade non-Hodgkin's lymphoma (NHL) in clinical trials. 62% of patients responded to retreatment in 1 small trial. black triangle In 2 studies, objective and complete response rates were higher and overall durations of response were significantly longer in patients treated with (131)I tositumomab compared with their last chemotherapy regimen. black triangle High dose (131)I tositumomab combined with autologous stem cell transplant produced an objective response rate of 86% in relapsed or refractory patients. black triangle (131)I tositumomab alone or in combination with fludarabine achieved an objective response rate of 100% in 2 preliminary reports in patients with previously untreated NHL. black triangle The dose-limiting toxicity of (131)I tositumomab is reversible myelosuppression, with approximately 18% of patients requiring haematological support in combined trial data. Other nonhaematological toxicities occur in approximately 20 to 40% of patients and include mild to moderate flu-like symptoms.