Incidence of AKI in Patients Admitted to Intensive Care Unit after Outpatient Chimeric Antigen Receptor T Cell Therapy: A Retrospective Single Center Analysis

Background: Chimeric antigen receptor T-cell (CAR-T) therapy represents a new therapeutic option for patients with refractory hematological malignancies. New paradigms are being implemented to perform them in the outpatient setting. However, the multiple side effects often require hospital admission in different levels of care, including intensive care unit (ICU). We performed a retrospective analysis of ICU utilization, development of acute kidney injury (AKI) and need for renal replacement therapy (RRT), in patients who underwent outpatient CAR-T therapy in a National Cancer Institutes (NCI)-designated cancer center. Methods: After obtaining IRB approval, we performed a retrospective chart review of 79 adult patients who underwent outpatient infusion of CAR-T therapy at Stephenson Cancer Center, Oklahoma City, between September 2019 and November 2023. We included patient whose indication for CAR-T was a hematological malignancy. We determined rates of ICU admission within 45 days after infusion, ICU admission diagnosis, development of AKI, need for RRT, length of stay and in-ICU mortality. Results: We identified 79 patients who underwent ambulatory, FDA-approved CAR-T therapy infusion during the study period. Within 45 days of CAR-T infusion, 12.6% (10/79) of patients required ICU admission (one patient was excluded due to inability to obtain medical records during ICU stay). ICU admission diagnosis included (with some patients with more than one): distributive shock secondary to CRS grade 3-4 (4/9), sepsis (2/9), encephalopathy secondary to ICANS (2/9), acute hypoxic respiratory failure (2/10), hypovolemic shock (1/9). Among patients admitted to ICU, 11% (1/9) developed AKI. Of note, this patient who developed AKI required RRT for a total of 12 days (until date of death). Mean ICU length of stay was 4.8 days (1-16), and in-ICU mortality rate was 11% (1/9). Conclusion: In this study, we found a lower rate of ICU admission compared to rates reported in similar studies. In majority of cases, ICU admission was due to CAR-T toxicities. Among patients admitted to ICU, one case developed AKI, and, notably, this case derived in fatal outcome. Kidney-specific toxicities are common with the advent of newer cancer therapies, which represents novel research pathways in nephrology.