Abstract Here, we report the results of the prospective cohort study EORTC‐CLG 58081 and compare them to the control arm of the randomized phase 3 trial EORTC‐CLG 58951, on which treatment recommendations were built. In both studies, patients aged 1–18 years with BCR::ABL1 negative acute lymphoblastic leukemia of the B‐lineage (B‐ALL) or T‐lineage (T‐ALL) were treated using a BFM backbone without cranial irradiation. Similarly to the control arm of 58951, prednisolone (PRED) 60 mg/m2/day was used for induction therapy, but a few modifications were made. Dexamethasone (DXM) was used in average‐risk 2 (AR2) T‐ALL and B‐ALL during induction, 10 and 6 mg/m2/day, respectively. Leucovorin rescue was delayed to 42 h instead of 36 h after initiation of high‐dose methotrexate, and a postconsolidation MRD time point was added to stratify patients. Between 2011 and 2017, 835 patients were prospectively enrolled in the 58081 study. Overall, the 5‐year event‐free survival (EFS) was 84.8% versus 83.6% (hazard ratio [HR], 0.96 [95% confidence interval [CI]: 0.76–1.21]) for 58081 versus 58951 considered as a control group, respectively, 84.3% versus 84.9% (HR, 1.06 [99% CI: 0.75–1.49]) in B‐ALL but 87.3% versus 76.6% (HR, 0.59 [99% CI: 0.28–1.24]) in T‐ALL. The comparison between the two studies regarding EFS differed by risk group (p = 0.012). The HR was 2.15 (99% CI: 0.67–6.85) for very low‐risk but 0.34 (99% CI: 0.13–0.89) for AR2. The particularly favorable results observed in the T‐ALLs and AR2 subgroups suggest the benefit of using DXM in specific patient groups and highlight the importance of risk stratification.
