P-072: Health Care Resource Utilization and Economic Burden of Cytokine Release Syndrome Management in Patients With Multiple Myeloma Receiving CAR-T Cell and Bispecific Antibody Therapies

Introduction: The multiple myeloma (MM) treatment landscape was transformed by chimeric antigen receptor (CAR)-T cell therapies and T-cell engaging bispecific antibodies (BsAbs); however, these immunotherapies can lead to cytokine release syndrome (CRS) resulting in substantial health care resource utilization (HCRU) and economic burden. We assessed real-world HCRU and costs among patients (pts) with MM with or without CRS post CAR-T/BsAb therapy.

Methods: This retrospective study using data from the Optum® Market Clarity Dataset (2020–2023) included adult pts in the United States who received CAR-T/BsAb therapy, had continuous enrollment ≥90 days pre- and post-index treatment date, and had an MM diagnosis during the 90-day baseline (BL) period. Two cohorts were evaluated: 1) pts experiencing any grade CRS (based on ICD-10 diagnosis codes) ≤30 days post-index, and 2) pts without CRS diagnosis nor severe CRS-associated symptoms/procedures post-index through follow-up. For the latter cohort, a randomly selected date using the same distribution of time to CRS as in the CRS cohort was designated as the start of the 30-day observation period for HCRU and costs. Outcomes included: hospitalizations, length of stay (LOS), emergency room (ER) and intensive care unit (ICU) visits, outpatient visits, and all-cause total (medication + medical) costs per-patient-per-month (PPPM). HCRU and costs were compared between cohorts using count data models and a generalized linear model with gamma distribution and log link, respectively. BL prognostic factors were balanced between cohorts using inverse probability of treatment weighting (IPTW).

Results: Of 219 eligible pts, 172 received CAR-T and 47 received BsAb therapy, of whom 118 (69%) and 18 (38%) experienced CRS, respectively. Among the 136 pts with CRS and 83 pts without CRS, 88% vs 59% were hospitalized; 21% vs 17% had ER visits; and 29% vs 13% were admitted to ICU. On a PPPM basis, pts experiencing CRS had 1.1 hospitalizations, 10.0 days LOS, and 0.5 ICU days, while pts without CRS had 0.7 hospitalizations, 6.7 days LOS, and 0.1 ICU days. Among pts with CRS, those treated with BsAb had fewer ICU days and lower total costs vs those treated with CAR-T. Regression with IPTW showed that, pts with CRS vs without CRS had 50% more hospitalizations with 4.7 days longer LOS and 3.7 times more ICU days PPPM; significant differences remain in sensitivity analysis adjusting for specific MM therapies. No significant differences were observed in other HCRU types evaluated. Total costs PPPM were significantly higher for the CRS vs no-CRS cohort after IPTW ($28,052 or 50% higher).

Conclusions: CRS following CAR-T/BsAb therapy led to higher HCRU and costs, mainly driven by inpatient and ICU admissions. CRS management imposes substantial economic burden on pts, treatment centers, and the healthcare system. Effective management of CRS that reduces duration or necessity of hospitalizations could save costs and inform decision-making in MM treatment.