Maintenance therapy following induction chemoimmunotherapy in patients with diffuse large B-cell lymphoma: current perspective

Maintenance therapy has proven efficacy in indolent non-Hodgkin lymphoma (NHL), yet its role in diffuse large B-cell lymphoma (DLBCL) is an area of ongoing investigation. While DLBCL is potentially curable, > 30% of patients relapse following front-line therapy and have a poor prognosis, especially those with refractory disease. Maintenance therapy holds promise to maintain response post-induction. Keyword searches were carried out in PubMed and congress abstracts of 'diffuse large B-cell lymphoma' and 'maintenance' and focused on phase II/III studies of maintenance following front-line induction. Although used in indolent forms of NHL, studies of maintenance therapy with rituximab in patients with DLBCL responding to front-line R-CHOP (rituximab/cyclophosphamide/doxorubicin/vincristine/prednisone) have not improved efficacy and are not recommended. Targeted agents enzastaurin and everolimus reported results from the phase III studies PRELUDE and PILLAR-2, respectively, both of which showed no proven maintenance benefit following front-line chemoimmunotherapy induction. Overall, the reported efficacy results with these agents in the maintenance setting do not outweigh the risks. Lenalidomide for maintenance has been reported in three studies. Results from two phase II trials on lenalidomide maintenance revealed positive outcomes in higher-risk patients following induction, resulting in improved progression-free survival in relapsed DLBCL patients who were ineligible for transplantation. First analysis from the phase III REMARC trial showed a significant improvement in progression-free survival for lenalidomide versus placebo, with no difference in overall survival, following front-line R-CHOP induction in elderly patients. Based on currently available studies of DLBCL maintenance therapies, initial results in front-line, as well as the relapsed setting, with immunomodulators such as lenalidomide show promise for further research to identify appropriate patients who would most benefit. Overall, this review of maintenance studies underscores the need for additional analyses of patient subtypes, clinical risk status, and molecular profiles, with careful consideration of study end points.