Overall and event-free survival in patients with KMT2Ar and infant ALL. (A) EFS KMT2Ar vs non-KMT2Ar. EFS for KMT2Ar patients at 6, 12, and 24 months was 55.3% (95% CI, 38.3% to 69.3%), 52.5% (95% CI, 35.6% to 66.9%), and 43.8% (95% CI, 27.6% to 58.8%), respectively, with a median EFS of 14.1 months (95% CI, 2.2 NE). EFS for non-KMT2Ar patients at 6, 12, and 24 months was 69.5% (95% CI, 64.6% to 73.9%), 58.0% (95% CI, 52.9% to 62.7%), and 47.0% (95% CI, 41.7% to 52.2%), respectively, with a median EFS of 20.2 months (95% CI, 13.9-28.4). P = .47. (B) OS KMT2Ar vs non-KMT2Ar. OS for KMT2Ar patients at 6, 12, and 24 months was 71.1% (95% CI, 53.9% to 82.8%), 57.7 (95% CI, 40.5% to 71.5%), and 51.9% (95% CI, 34.9% to 66.5%), respectively, with a median OS of 25.3 months (95% CI, 7.9 NE). OS for non-KMT2Ar patients at 6, 12, and 24 months was 85.6% (95% CI, 81.6% to 88.7%), 76.3 (95% CI, 71.7% to 80.3%), and 65.9% (95% CI, 60.6% to 70.7%), respectively, with a median OS of 51.9 months (95% CI, 42% NE). P = .02. (C) EFS infant ALL vs noninfant ALL. EFS for infant patients at 6, 12, and 24 months was 55.2% (95% CI, 35.6% to 71.0%), 55.2% (95% CI, 35.6% to 71.0%), and 50.9% (95% CI, 31.5% to 67.5%), respectively, with a median EFS not reached. EFS for noninfant patients at 6, 12, and 24 months was 69.2% (95% CI, 64.3% to 73.5%), 57.7% (95% CI, 52.6% to 62.5%), and 46.5% (95% CI, 41.2% to 51.6%), respectively, with a median EFS of 19.5 months (95% CI, 13.9-27.0). P = .88. (D) OS Infant ALL vs noninfant ALL. OS for infant patients at 6, 12, and 24 months was 69% (95% CI, 48.8% to 82.5%), 58.2% (95% CI, 38.3% to 83.8%), and 54.1% (95% CI, 34.2% to 70.3%), respectively, with a median OS of 35.8 months (95% CI, 5.6 NE). OS for noninfant patients at 6, 12, and 24 months was 85.4% (95% CI, 81.5% to 88.5%), 75.8 (95% CI, 71.2% to 79.8%), and 65.4% (95% CI, 60.2% to 74.2%), respectively, with a median OS of 49.1 months (95% CI, 42.0 NE). P = .15.