Predictors of 30-day Readmissions Post-CAR-T in Patients with Relapsed/Refractory Multiple Myeloma using the United States Nationwide Readmission Database

B-cell maturation antigen (BCMA)-directed chimeric antigen receptor T-cell (CAR-T) therapy has changed the therapeutic landscape of relapsed/refractory multiple myeloma (RRMM). Despite the efficacy, these products have been associated with an adverse effect profile including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), which require monitoring and early intervention. This is a retrospective cohort study using the National Readmission Database (NRD) aimed at evaluating hospital outcomes, economic burden, and readmission risks for ide-cel and cilta-cel in a real-world cohort of RRMM patients treated across various hospitals in the USA. During the study period,1291 RRMM patients receiving BCMA CAR-T cell therapy were identified in the United States. After excluding December admissions to allow for 30-day follow-up, 1180 patients were included in the final analysis. We found a 17% readmission rate within 30 days, with immune effector cell–related complications and infections constituting the most common causes of readmission. These findings highlight the significant clinical and economic burden of post-CAR-T care, despite the transformative impact of these therapies on outcomes for RRMM.