P033 | LOW MORTALITY IN INTENSIVE CARE UNIT FOLLOWING CAR-T CELL THERAPY: INSIGHTS FROM A MONOCENTRIC REAL-WORLD EXPERIENCE

Background Chimeric Antigen Receptor T-cell (CAR-T) therapy has become a highly effective treatment for patients with refractory hematological malignancies. Despite frequent adverse events that are typically reversible, up to 30% of patients require ICU admission, with reported ICU mortality rates ranging from 27% to 35%1. This study aimed to evaluate mortality rate and outcomes in patients admitted in ICU. Methods We performed a retrospective, single-center analysis of 146 adult patients who underwent CAR-T therapy at Humanitas Research Hospital between November 2019 and December 2024. Management of CRS and ICANS followed institutional guidelines2. Results CRS occurred in 125 patients (86%), with 6 patients (4%) experiencing grade 3 CRS; no grade 4 CRS events were observed. ICANS was documented in 41 patients (28%), with 17 patients (11%) developing grade ≥3 ICANS. Twenty-five patients (17%) required ICU care (median ICU stay: 2.5 nights). The main reasons for ICU admission were ICANS (68%), CRS (20%), infections (4%), and progressive disease (8%). The infection rate among ICU patients was 28%. ICU interventions included vasoactive support (6 patients), oxygen therapy (16 patients: 6 with high-flow nasal cannula, 10 with conventional oxygen therapy, and 2 with non-invasive ventilation), intubation in 7 patients (mainly for grade 4 ICANS), and tracheostomy in 2 patients due to prolonged mechanical ventilation. Three patients required ICU readmission for grade 4 ICANS, septic shock, and acute respiratory failure from platypnea-orthodeoxia syndrome. The early mortality rate (<30 days post-CAR-T) was 2%, with two deaths from infections and one from grade 4 ICANS. Only one patient died in the ICU, resulting in an ICU mortality rate of 4%. After a median follow-up of 9.4 months, the 1-year overall survival (OS) rate was 71.4%, with no significant difference between ICU (65.2%) and non-ICU patients (75.6%) (p=0.66). The 1-year progression-free survival (PFS) rate was 54.5%, with rates of 50.3% in ICU and 58.2% in non-ICU patients (p=0.60). Conclusions In this single-center study, the ICU mortality rate following CAR-T therapy was lower than previously reported. Long-term outcomes, including OS and PFS, were similar between ICU and non-ICU patients, suggesting that optimized patient selection, early toxicity management, and close ICU collaboration may reduce severe complications. ICANS emerged as the leading cause of ICU admission, unlike earlier studies.