Efficacy of Rituximab in the Setting of Steroid-Refractory Chronic Graft-versus-Host Disease: A Systematic Review and Meta-Analysis

Increased insight into the role of B lymphocytes in the pathophysiology of graft-versus-host disease has led to a number of studies assessing the efficacy of the anti-CD20 monoclonal antibody (mAb) rituximab in treating steroid-refractory chronic graft-versus-host disease (cGVHD). Findings vary greatly among these studies, however. We conducted a systematic review to summarize the totality of evidence on the efficacy of rituximab in steroid-refractory cGVHD. We performed a PubMed search and contacted experts in the field to identify relevant studies. Endpoints included overall response rate (including organ-specific) and ability of rituximab to allow dosage reduction of immunosuppressive therapies. Data were pooled under a random-effects model. Seven studies (3 prospective and 4 retrospective, with a total of 111 patients) met the inclusion criteria. The pooled proportion of overall response was 0.66 (95% confidence interval=0.57 to 0.74). There was no heterogeneity among the pooled studies. Response rates were 13% to 100% for cGVHD of the skin, 0 to 83% for cGVHD of the oral mucosa, 0 to 66% for cGVHD of the liver, and 0 to 38% for cGVHD of the lung. Common adverse events were related to infusion reactions or infectious complications. The relatively small number of patients and the varying criteria for reporting organ response and dosage reduction of steroids, among other limitations, hinders our ability to reach definitive conclusions on the overall efficacy of rituximab for cGVHD involving other organs.