Inpatient and Intensive Care Unit Resource Utilization after CD19-Targeted Chimeric Antigen Receptor T-Cell Therapy (CART19) for Pediatric Acute Lymphoblastic Leukemia (ALL)

Background CART19-related toxicities may require treatment inpatient or in the ICU. We sought to describe inpatient/ICU resource utilization within 30 days of CART19 infusion and evaluate trends in resource utilization from 2012-2019. Methods We identified patients (pts) with ALL treated with CART19 on a clinical trial (NCT01626495, NCT02906371, and NCT02374333) or with the commercial product, tisagenlecleucel, at Children's Hospital of Philadelphia. Demographic, pharmacy, and inpatient data were extracted from the EHR from day of infusion (d0) to d+30 using a semi-automated EPIC data query tool. The Virtual Pediatric Systems database was queried for resource utilization data and PRISM 3 and PIM 2 severity of illness scores. Log-binomial and linear regression were used to estimate the association of patient characteristics with inpatient/ICU admission and inpatient/ICU length of stay (LOS). Similar models were used to estimate trends over time. Results The analyses included 213 pts. Median age was 12y (range 1-29y); 60% were male. Prior to CART19, 42% had an alloHCT. Pre-infusion, 19% had high tumor burden (HTB), defined as bone marrow blasts ≥40%. From 2012-2019, the proportion of pts with prior alloHCT or HTB decreased (Table 1). CART19 was infused in the outpatient setting in 198 (93%) pts. From d0 to d+30, 149 (70%) had ≥1 inpatient admission, starting at a median of d+2 (IQR +1 to +6). Among admitted pts, median cumulative inpatient LOS was 7d (IQR 4-13). From 2012-2019, there were linear trends toward decreases in proportion of pts admitted (p ICU admission was required for 49 (23%) pts, starting at a median of day +5 (IQR +4 to +7). ICU admission was more frequent for pts with HTB [HTB, 68% (95% CI, 52-81) vs. low burden, 11% (95% CI, 7-17), p Other than HTB, baseline characteristics were not associated with inpatient/ICU admission or LOS. Conclusion In a cohort of 213 pediatric pts, over 90% were safely infused with CART19 in the outpatient setting. Though 70% required at least one admission, the proportion of pts admitted to the hospital or ICU and cumulative inpatient LOS decreased over the past 7 years.