The study is designed as an intra-patient dose escalation employing a total dose range (over 2 doses, Dose 1 and Dose 2) of between 5 x 106 CD19CAR T-cells and 1.1 x 109 CD19CAR T-cells. The study will evaluate ATIMP safety and efficacy and the duration of disease response in adults with high risk / relapsed CD19+ B-ALL.