Maintenance rituximab after autologous stem cell transplantation in patients with mantle cell lymphoma

High-dose therapy and autologous stem cell transplantation (ASCT) improves outcomes for patients with mantle cell lymphoma (MCL), but relapse ultimately occurs in most patients. Recently presented interim results from a phase III prospective trial suggest maintenance rituximab (MR) after ASCT for MCL improves progression-free survival (PFS). The maturation of these data and any benefit of MR on overall survival (OS) remain to be defined. In this retrospective study, we examined a cohort of consecutive patients with MCL that underwent ASCT for MCL at our center and evaluated their outcomes according to whether they received MR after ASCT (n = 50) or did not (n = 107). MR was treated as a time-dependent covariate to account for variation in timing of its initiation. MR was associated with an improved PFS [hazard ratio (HR) 0.44; confidence interval (CI) (0.24–0.80), P = 0.007] and overall survival (OS; HR 0.46; CI 0.23–0.93, P = 0.03) following a multivariate adjustment for confounding factors with a median follow-up of ∼5 years. Grade 4 neutropenia was increased (34% versus 18%, P = 0.04) in the MR group, but no effect on the rate of mortality unrelated to relapse was observed. These data support that MR after ASCT for MCL confers a benefit in PFS and additionally suggest it may improve OS. General application of this strategy will require confirmation of benefit in prospective randomized trials.