Study flowchart of 149 study patients with Ph^– B-ALL. The integrated clinical and MRD-based risk stratification allowed for the assignment of 132 CR patients to allo-HSCT or 2-year maintenance chemotherapy. CR was achieved after chemotherapy cycles 1 or 2 (patients not in CR at this stage were off study). Blin-1 was intentionally administered before the application of risk-oriented therapy. FUP, follow-up.