[Safety and efficacy of CD19-targeted CAR-T cells in 14 patients with refractory/relapsed Philadelphia chromosome-positive acute B-precursor lymphoblastic leukemia].

Objective

This study aimed to examine the safety and efficacy of CD19 chimeric antigen receptor T cell (CD19 CAR-T) therapy in relapsed/refractory Philadelphia chromosome-positive acute B-precursor lymphoblastic leukemia (R/R Ph(+) B-ALL) .

Methods

The clinical data of 14 patients with R/R Ph(+) B-ALL treated with CD19 CAR-T cell therapy from November 2016 to April 2019 were retrospectively analyzed.

Results

Among the 14 patients in this study, 7 were male and 7 were female, with a median age of 33 (7-66) years old. The efficacy was evaluated on the 28th day following CAR-T cells infusion; the overall response rate was 100.0% (14/14) , the complete response (CR) rate was 92.9% (13/14) , and the partial response (PR) rate was 7.1% (1/14) . After CAR-T cells infusion,12 cases (85.7%) developed cytokine release syndrome (CRS) : 1 case of grade 1 CRS, 4 cases of grade 2 CRS, 6 cases of grade 3 CRS, and 1 case of grade 4 CRS. Moreover, one case developed CAR T-cell-related encephalopathy syndrome (CRES) ; 14 cases had Ⅲ-Ⅳ hematological toxicity; and 13 CR cases had B cell dysplasia. These adverse reactions were all controllable. The median follow-up time was 441 (182-923) d. The median overall survival (OS) and progression-free survival (PFS) were 515 [95% confidence interval (CI) 287-743] days and 207 (95% CI 123-301) days, respectively.

Conclusion

CD19 CAR-T cell therapy is safe and effective for R/R Ph(+) B-ALL treatment. However, the long-term efficacy needs to be further improved.