Therapeutic effects of chimeric antigen receptor T cells (CAR-T) on relapse/refractory diffuse large B-cell lymphoma (R/R DLBCL): a meta-analysis

OBJECTIVE: Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL). This study aimed to systematically evaluate the efficacy of chimeric antigen receptor T cells (CAR-T) in treating relapse/refractory DLBCL (R/R DLBCL) and associated complete-remission rate (CR). MATERIALS AND METHODS: PubMed, Cochrane Library, CNKI, VIP, CBM, and Wanfang databases were searched, and literature was collected up to January 2019. According to inclusion criteria and exclusion criteria, two researchers independently reviewed and screened literature, extracted required data and crossly checked them. This meta-analysis was conducted using RevMan 5.3 software. RESULTS: This study finally included 13 English literatures and 263 cases. There was no heterogeneity among all these studies, therefore, fixed effect model was used. Meta-analysis findings showed that total CR rate of R/R DLBCL treated with CAR-T was 46.8% (95% CI: 0.408-0.533). Subgroup analysis showed that CR rate of CD28 group was slightly higher [52.5%, with 95% confidence interval (CI): 0.441-0.602] compared to that of 4-1BB group (41.5%, with 95% CI: 0.324-0.510). CR rate of CD19 group was slightly higher (49.2%, with 95% CI: 0.4290.556) compared to that of CD20 group (42.2%, with 95% CI: 0.231-0.639). Funnel chart of total CR rate, co-stimulatory factor, and target antigen demonstrated fundamental symmetry. Moreover, age, HSCT administration, CAR-T cell counts, and drug pre-treatment also affected immunotherapy on CAR-T on R/R DLBCL. CONCLUSIONS: CAR-T treatment for R/R DLBCL demonstrated evident curative effect and high complete remission rate. CAR-T cell immunotherapy would be expected to become mainstream therapy for hematolymph system tumors.