Healthcare Resource Utilization and 2022 Cost Update of Cytokine Release Syndrome and Neurotoxicity in Patients with Relapsed/Refractory Multiple Myeloma (RRMM) Receiving Idecabtagene Vicleucel (IDE-CEL, BB2121) in KarMMa

OBJECTIVES: To estimate healthcare resource utilization (HCRU) and cost of cytokine release syndrome (CRS) and/or neurotoxicity (NT) management by grade among patients with relapsed/refractory multiple myeloma (RRMM) who received ide-cel, a BCMA-directed CAR T-cell therapy, in the KarMMa clinical trial (NCT03361748).

METHODS: This study analyzed KarMMa patient case reports from data to estimate HCRU and costs of CRS/NT management following ide-cel administration. A micro-costing methodology was employed: 1) HCRU per study CRS/NT management guidelines (eg, inpatient [IP] and intensive care unit [ICU] days, procedures, diagnostics, medications) was calculated from CRS/NT onset through resolution by grade and whether concurrent/nonconcurrent in patients who experienced both, and 2) associated costs were applied to each HCRU. Unit costs were measured from the healthcare system perspective using peer-reviewed literature and public sources and adjusted to 2022 United States dollars.

RESULTS: Any-grade CRS and/or NT occurred in 83.6% (107/128) of patients who received ide-cel in KarMMa. Grade breakdown was as follows: CRS only: grade 1 (n=52), grade 2 (n=29), grade 3 (n=2), grade 4 (n=1); NTs only: none; both CRS and NT: grade ≤2 (n=14), grade ≥3 (n=9). All 107 patients had a standard IP stay and 19 (17.8%) were admitted to the ICU. Median total costs were as follows: CRS only: grade 1= $20,663, grade 2= $24,887, grade 3=$82,135, grade 4=$97,656; concurrent CRS/NT: grade ≤2, $32,527, and grade ≥3, $65,535. Costs were primarily driven by facility-related resource use and fees. Total CRS/NT costs ranged substantially ($5,749–$315,629), and generally increased with severity. Costs were highest among patients experiencing grade 4 CRS only and were consistently lower among patients with grade ≤2 CRS/NT than for patients with higher-grade CRS/NT.

CONCLUSIONS: Higher-grade CRS/NT management costs were higher than those for patients with lower-grade CRS/NT, however few patients incurred such costs. Therapies associated with low-grade CRS/NT may potentially limit HCRU and costs.