Treatment with yttrium 90 ibritumomab tiuxetan at early relapse is safe and effective in patients with previously treated B-cell non-Hodgkin's lymphoma

Yttrium 90 (90Y) ibritumomab tiuxetan (Zevalin), a radiolabeled monoclonal antibody against the CD20 antigen, is indicated for the treatment of patients with relapsed or refractory low-grade, follicular, or transformed B-cell non-Hodgkin's lymphoma (NHL), including patients with rituximab-refractory follicular NHL. Data on 211 patients treated in four clinical trials were analysed to compare the efficacy and safety of 90Y ibritumomab tiuxetan when it was used after the first relapse of NHL and when it was used after two or more prior therapies. Sixty-three patients (30%) were treated with 90Y ibritumomab tiuxetan after their first relapse and 148 (70%) after two or more prior therapies. Demographics, disease characteristics and the frequency of adverse events were similar in all groups, with the exception of a higher rate of marrow involvement in first-relapse patients than in patients with two or more prior therapies (57% vs. 39%; P < 0.05). The complete response rate [confirmed (CR) and unconfirmed (Cru...