从高比例急性髓系白血病原始细胞的白细胞分离产物中学术化生产抗CD19 CAR-T细胞

This report describes the manufacturing of anti-CD19 chimeric antigen receptor-T (CAR-T) cells in an academic setting for a patient with a high tumour burden (>90%) who was referred for CD19+ acute myeloid leukaemia (AML). A 30-year-old woman with refractory acute myeloid leukaemia (AML) was found with 94% circulating blasts, 79% of which were considered CD19 positive upon initial screening. She was selected as a candidate for inclusion in an anti-CD19 CAR-T cell clinical trial. In order to promptly offer a therapeutic option to this patient with active disease, an apheresis product was magnetically enriched to >90% T cells, enabling manufacturing of a clinically compliant CAR-T cell dose (> 1 × 10^6 CAR-T cells/kg). A potency assay confirmed CD19-specific cytotoxic activity. Yet, further in-process flow cytometry quality controls unexpectedly revealed that the AML blasts did not actually express CD19, which was confirmed by reverse transcriptase multiplex ligation-dependent probe amplification (RT-MLPA), eventually rendering the patient ineligible for treatment. This case demonstrates the feasibility of manufacturing functional CAR-T cells from an apheresis product containing less than 3% T cells and indicates that a second target validation should be considered prior to recruitment when targeting a lymphoid marker in rare cases of myeloid leukaemia.