Dose 1a* (BM blasts≤20%): 1x108 CD19CAR T-cells (plus 20% for thawing losses) Dose 1b* (BM blasts>20%): 1x107 CD19CAR T-cells (plus 20% for thawing losses) Dose 2* (all patients, in the absence of clinically severe CRS): dosing range between minimum dose of ≥5 x 106 CD19CAR T-cells (plus 20% for thawing losses) and maximum dose of ≤1x109 CD19CAR T-cells (plus 20% for thawing losses)