Efficacy and safety of chimeric antigen receptor-T cells in the treatment of B cell lymphoma: a systematic review and meta-analysis

BACKGROUND: Conventional treatment has limited efficacy in relapsed/refractory B-cell lymphoma. Since chimeric antigen receptor T-cell (CAR-T) technology has shown high safety and results in high remission rates, we investigated its efficacy and safety in B-cell lymphoma treatment and analyzed potential affecting factors to provide evidence for therapeutic strategies and applications. METHODS: We searched databases including PubMed, Embase, and Cochrane up to July 2019. Meta-analysis 1 was conducted to study the efficacy of CAR-T cell for treating B-cell lymphoma, measuring the response rate and complete remission rate as outcomes. Sub-group analysis was performed for age, pathological type, target antigen, co-stimulatory molecule, and conditioning chemotherapy. Meta-analysis 2 was undertaken on the safety of the treatment with the incidence rate of toxicity (cytokine-releasing syndrome [CRS], neurotoxicity) as an outcome. RESULTS: Seventeen studies were included in the systematic review and meta-analysis. It was found that CAR-T cells had good therapeutic effects in the following cases: B-cell lymphoma (patients ≥65 years old); diffuse large B-cell lymphoma pathological type; patients with treatment target antigen other than CD19; patients treated with co-stimulatory molecules other than CD28, including 4-1BB+CD28 or 4-1BB; and patients treated with cyclophosphamide/fludarabine pre-treatment protocol conditioning chemotherapy. Although the CRS and neurotoxicity incidences were high, most were reversible with minimal risk of death. CONCLUSION: CAR-T cell treatment is safe for clinical application; however, toxicity effects should be monitored.