Incidence of AKI and Kidney Replacement Therapy (RRT) after Outpatient Chimeric Antigen Receptor T (CAR-T) Cell Therapy in Patients with Hematological Malignancies

Background: AKI is characterized by an abrupt loss of kidney function resulting in decreased GFR, reduced urine output, and increased serum creatinine. CAR-T therapy is a newer cancer immunotherapeutic treatment that utilizes genetically altered cytotoxic T cells in destroying cancer cells. There have been very few studies studying the repercussions of inpatient CAR-T therapy on kidneys, but so far no studies have covered the renal safety profile of outpatient CAR-T therapy. We performed a retrospective analysis on incidence of AKI, resolution vs progression of disease requiring RRT and devolpment of CKD, in patients who underwent outpatient CAR-T therapy at our institute. Methods: We obtained IRB approval and identified 79 adult patients who underwent outpatient CAR-T therapy between 9/2019 to 11/2023 for hematological malignancies at our National Cancer Institutes (NCI)-designated cancer center. Then we performed a retrospective chart review and determined the rates of hospital admissions and development of AKI within 7 days of CAR-T infusion, and followed the hospital course to assess the need for RRT, resolution of AKI, and progression to CKD. We also looked at the past medical history to assess if patients had preexisting diabetes, hypertension, and CKD. Results: Out of the 79 patients who underwent outpatient CAR-T therapy infusion, 74.6 % ended up being admitted in the hospital. Within 7 days of infusion, 3 patients developed AKI, requiring hospitalization. Among these, one patient had preexisting CKD, and developed AKI on CKD. All three had hypertension on baseline, and interestingly none had diabetes. Incidence of AKI in all patients was at 3.7 %, whereas incidence of AKI in hospitalized patients was at 5.08%. 1 patient developed severe AKI requiring RRT, bringing incidence rate of RRT at 1.26 % among all patients and 33% among the AKI group. Kidney function returned to baseline within 30 days in two of our patients, while one patient passed away during the hospitalization. None of our patients progressed to CKD. Conclusion: We found a lower rate of AKI compared to rates reported in previous studies for patient who underwent inpatient CAR-T therapy, favoring the theory that outpatient CAR-T has a less severe side effect profile than inpatient CAR-T.