Estimating costs of adverse events (AEs) and healthcare resource use (HRU) in patients with relapsed or refractory diffuse large B-cell lymphoma (r/r DLBCL) receiving tisagenlecleucel (tisa-cel) and axicabtagene ciloleucel (axi-cel): A summary of real-world evidence.

e19551 Background: The AE rates and HRU reported in multiple real-world evidence (RWE) studies of chimeric antigen receptor T-cell (CAR-T) therapies tisa-cel and axi-cel in r/r DLBCL have differed from those in their clinical trials. However, the cost implications from these findings are not well understood in existing literature. This study summarizes information from these RWE studies of tisa-cel and axi-cel and quantifies the associated costs. Methods: A literature review was conducted to identify RWE studies reporting AE rates and HRU of tisa-cel and axi-cel in the United States (US). AE rates and HRU were summarized and the associated costs were estimated using a micro-costing approach. Costs of AE management included hospitalization and pharmacy costs, such as intensive care unit (ICU) stays, inpatient admissions, and medications for the treatment of cytokine release syndrome (CRS) and neurotoxicity events (NE). HRU costs included hospitalization, ICU stays, and outpatient visit costs. Unit costs were from public health databases that are representative of US healthcare system and from literature. Costs were inflated to 2020 US dollars. A range was reported to present evidence if inputs are available from multiple studies. Results were summarized for tisa-cel and axi-cel separately. Results: Four publications were identified: Jaglowski 2019, Pasquini 2019, Riedell 2019, and Jacobson 2020. Across studies, grade 3+ CRS and NE occurred in 1%-4% and 0%-5% of tisa-cel-treated patients and 7%-16% and 20%-35% of axi-cel-treated patients, respectively. Tocilizumab usage was reported in 14%-20% of tisa-cel- and 62%-71% of axi-cel-treated patients. CAR-T infusion was inpatient for 36% of tisa-cel- and 92%-100% of axi-cel-treated patients. The median hospitalization days was 2 for tisa-cel and 15-16 for axi-cel. ICU transfer was observed for 7% and 28%-38% of tisa-cel- and axi-cel-treated patients, respectively, with median stays of 4 and 5 days, respectively. The median number of outpatient visits within 28 days after infusion was 6 for tisa-cel and 4 for axi-cel. The total estimated costs for managing AEs per patient were $843-$1,962 for tisa-cel and $5,979-$10,878 for axi-cel. The total estimated HRU costs per patient were $3,321 for tisa-cel and $32,394-33,166 for axi-cel. Conclusions: RWE studies suggest that patients with r/r DLBCL receiving tisa-cel had numerically lower AE rates, HRU, and cost burden than those receiving axi-cel in the US. The additional cost burden for axi-cel was primarily driven by the incremental ICU and hospitalization care due to a higher proportion of inpatient infusion among patients receiving axi-cel. Further research is warranted to compare the costs associated with the two CAR-Ts in r/r DLBCL.