Outcomes of patients with high and low disease burden, with and without HLH-LTs. (A) OS and RFS for group with no or low pre–CAR T-cell infusion disease burden without HLH-LTs (no/low disease, no HLH-LT), high disease burden without HLH-LTs (high disease, no HLH-LT), and high disease with HLH-LTs (high disease, with HLH-LT). High pre–CAR T-cell infusion disease burden is defined as ≥ 5% BM blasts, the presence of extramedullary disease, or evidence of leukemia in the peripheral blood. Low disease burden is detectable BM disease <5% without high disease burden criteria. No patients with no disease or low disease burden developed HLH-LTs. (B) OS for patients with 5% to <50% BM blasts (5% to <50%), and ≥50% BM blasts (≥50%), with and without HLH-LTs. Survival curves were generated with the Kaplan-Meier method and compared using log-rang tests with significance level of P< .05.