CART序贯二次异基因造血干细胞移植治疗移植后复发急性B淋巴细胞白血病41例临床分析

OBJECTIVE: To study the clinical efficacy of chimeric antigen receptor T-cell（CART）treatment followed by a second allogeneic hematopoietic stem cell transplantation（allo-HSCT）in patients with B-cell acute lymphoblastic leukemia （ALL） who relapsed following the first HSCT. METHODS: Retrospective analysis of the clinical characteristics and prognosis of 41 patients with B-cell ALL who received a second allo-HSCT from October 2015 to June 2020 in Hebei Yanda Lu Daopei Hospital. After the first HSCT, all patients received CD19-CART, or CD22-CART treatment following a relapse of bone marrow morphology or extramedullary leukemia. RESULTS: A total of 41 patients（male, 21; female, 20）were included in this study. The median age at the second HSCT was 16（3–46）years. There were 31 cases of bone marrow recurrence（75.6％）, 5 cases of extramedullary recurrence（12.2％）, and 5 cases of bone marrow and extramedullary recurrences（12.2％）. After relapse, 35 patients（85.4％）received CD19-CART treatment, 2 patients received CD22-CART treatment（4.9％）, and 4 patients received CD19-CART and CD22-CART treatments（9.8％）. The expected 3-year overall survival（OS）, leukemia-free survival, cumulative relapse incidence, and non-relapse mortality（NRM）of patients after the second HSCT were 48.9％（95％ CI 23.0％–70.6％）, 41.8％（95％ CI 17.3％–64.9％）, 8.8％（95％ CI 2.9％–26.4％）, and 51.1％（95％ CI 31.2％–83.6％）, respectively. The 1-year OS of patients who relapsed ≤6 months and >6 months after the first HSCT were 45.0％（95％ CI 12.7％–73.5％）and 75.0％（95％ CI 51.4％–88.8％）（P＝0.017）, respectively. CONCLUSION: CART bridging in the second HSCT enables some B-cell ALL patients who relapsed after the first HSCT to achieve long-term survival. However, because of the high NRM, further modifications could help improve the outcome.