Background: Adverse events (AEs) such as CRS and NEs of varying severity have been associated with CAR T cell therapies, including liso-cel, an autologous, CD19-directed, 4-1BB CAR T cell product administered at equal target doses of CD8 +and CD4 +CAR +T cells. Liso-cel has previously demonstrated clinically meaningful responses in patients with R/R FL in the phase 2 TRANSCEND FL study (NCT04245839). In addition, previous research among patients with large B-cell lymphoma has suggested an acceptable safety profile with few grade ≥ 3 CRS/NEs, and safety data from TRANSCEND FL are in line with this larger dataset. However, there is limited to no research published on estimates of HCRU and costs related to the management of CRS/NEs among liso-cel-treated patients with FL. This analysis evaluated HCRU and estimated costs of managing CRS/NEs by grade and concurrency for patients with R/R FL who received liso-cel treatment in the TRANSCEND FL study.