Abbreviated dose rituximab for immune-mediated hematological disorders

As rituximab, a monoclonal antibody targeting CD20, depletes B cells, there is considerable interest in its use in immune-mediated disorders. The majority of studies employ a four-dose regimen based on practice in lymphoma therapy. We describe our experience with one or two doses of 375 mg/m(2) of rituximab in 12 patients with relapsed and refractory immune-mediated hematological disorders. Eleven patients (92%) achieved a complete remission that has been sustained in 7 for a median of 14.5 (10.5-22) months. Four patients (36%) relapsed after responses of 1-18.5 months. This preliminary experience suggests that one or two doses of rituximab may have response and relapse rates comparable to multidose regimens while potentially providing considerable cost savings. Further prospective studies are planned.