A systematic review of comparative schedule-related toxicities with maintenance rituximab in follicular and mantle cell lymphomas

We conducted a systematic review of grade 3/4 adverse events (AEs) reported in prospective trials enrolling patients with follicular lymphoma (FL) and mantle cell lymphoma (MCL) receiving maintenance rituximab (MR). Random-effects models were used to calculate summary estimates and 95% confidence intervals for the proportion of AEs occurring during MR. Differences by induction program, histology, setting and MR schedule were examined by stratified analyses and univariate random-effects meta-regression. Eleven trials met the search criteria, with nine sufficiently reporting AEs during the MR phase. Of 1009 patients receiving MR, the proportion experiencing cumulative grade 3/4 toxicity was 24% (95% confidence interval [CI]: 14-36%). Patients receiving MR every 6 months as four weekly infusions for 2 years had significantly less toxicity compared with those receiving MR every 2 months (10% vs. 28%; p = 0.035). Patients treated with rituximab alone during induction had fewer toxicities compared to those treated with rituximab plus chemotherapy induction (12% vs. 35%; p = 0.031). Myelosuppression and infections were the most common toxicities. Our literature analysis suggests that MR given every 6 months and rituximab alone as induction may be associated with fewer grade 3/4 AEs for patients with FL and MCL; however, assessing the true independent impact of induction regimens and schedule on toxicity will require prospective trials.