Here, we report pre-clinical and first-in-human phase I trial results of CD19 STAR-T cell therapy for CD19+ R/R B-ALL...Patients received a conditioning regimen of IV fludarabine (25mg/m2/d) and cyclophosphamide (250mg/m2/d) for 3 days followed by a single STAR T-cell infusion...A high CR could be achieved on day 14 with low toxicity. Longer-term observation of these patients and studies of larger patient cohorts are warranted.