Treatment of chronic steroid-refractory graft-versus-host disease with low-dose rituximab.

Rituximab, an anti-CD20 chimeric monoclonal antibody, is widely used in hematologic malignancies and has been introduced as a therapeutic option in autoimmune disorders. In recent studies, rituximab has shown promising activity in steroid-refractory chronic graft-versus-host disease (cGvHD) at a weekly dose of 375 mg/m2. We now report on 13 subjects after peripheral blood stem-cell transplantation receiving low-dose rituximab (50 mg/m2) for steroid-refractory cGvHD and autoimmune disorders (membranous glomerulonephritis and immune thrombocytopenic purpura). The overall response rate was 69%, including two patients with complete responses. In accordance, we observed clearance of peripheral blood B cells even after the first dose of rituximab in four patients. We conclude that low-dose rituximab seems to be active and safe in intensively pretreated patients with steroid-refractory cGvHD.