Efficacy and safety of CD19 chimeric antigen receptor T cells in the treatment of 11 patients with relapsed/refractory B-cell lymphoma: a single-center study

BACKGROUND: No effective treatment exist for patients with relapsed and refractory B-cell lymphoma, until the advent of anti-CD19 chimeric antigen receptor (CAR) T-cells. Therefore, this study aimed to explore the factors affecting the efficacy of anti-CD19 CAR T-cell and the adverse reactions of the therapy. METHODS: We recruited 11 patients with relapsed and refractory B-cell lymphoma. The number of anti-CD19 CAR T-cells, proliferation, and adverse reactions were recorded in detail, to explore the relationship between the factors affecting the efficacy of anti-CD19 CAR T-cell and the long-term survival of patients. RESULTS: The 11 patients in our study had a total overall response rate of 100%, after receiving anti-CD19 CAR T-cells. The median follow-up was 253 days (range, 130–1,017 days). The median overall survival (OS) and median progression-free survival (PFS) were not reached. After 3 months of treatment, the complete remission (CR) rate was 63.6% (7/11). As of December 7, 2019, 5 patients had maintained CR for a period exceeding 1 year, including 2 patients who had maintained CR for more than 1,000 days. The patients who received 3 or 4 lines of chemotherapy were more likely to have sustained remission than the patients who received <2 or >4 lines of chemotherapy. Each of the 4 patients in the study who had diffuse large B cell lymphoma (DLBCL) progression all had high myc protein expression (positive incidence: 30–80%). The incidence of Grade 2 cytokine release syndrome (CRS) was 36.4% (4/11), and Grade 3 CAR T-cell-related encephalopathy syndrome (CRES) was experienced by 1 patient. The occurrence of adverse reactions was not significantly related to the infusion dose, peak amplification time, or maximum copy amount. The immunoglobulin levels of the four patients who died showed a significant downward trend. Interleukin-1β (IL-1β), interferon-γ (IFN-γ), interleukin-10 (IL-10), and interleukin-17A (IL-17A) appeared to be associated with the occurrence of CRS and CRES. CONCLUSIONS: Anti-CD19 CAR T-cell treatment is a new therapy for patients with relapsed and refractory B-cell lymphoma. Among the small sample size in this study, it demonstrated high efficiency and safety.