Objectives: Published data detailing healthcare resource use and costs after 2L systemic treatment initiation for r/mCC are sparse. This study describes real-world healthcare costs among immune checkpoint inhibitor (ICI)-naive, 2L-initiating patients with r/mCC.

Methods: This was a retrospective cohort study of adult patients with r/mCC (CC diagnosis from years 2016ꟷ2021) who progressed on 1L systemic treatment and initiated 2L in the US-based Optum^® Clinformatics™ Data Mart database. Patients with ICI exposure before 2L initiation or other primary malignancies during 1L treatment were excluded. Per-patient-per-month (PPPM) healthcare costs (adjusted to 2021 US dollars) and healthcare resource utilization were described by 2L versus third-line (3L) treatment phase and on-treatment versus off-treatment periods. End-of-life costs within 30 days preceding death were characterized.

Results: In total, 147 patients with r/mCC initiating 2L treatment met inclusion and exclusion criteria (median age, 59 years). Of these, 55 initiated 3L and 69 died during a median follow-up of 6.8 months (Quartiles 1–3, 3.4–15.1 months). The mean total all-cause PPPM costs during 2L and 3L phases were $19,284 and $26,771, respectively, with higher total all-cause costs during the on-treatment versus off-treatment periods (mean: 2L, $20,931 vs $13,283; 3L, $28,093 vs $15,431). Inpatient PPPM costs were higher during 3L versus 2L phases (mean $11,956 vs $6912, respectively). Within each line of treatment, inpatient all-cause PPPM costs were higher during off-treatment periods than on-treatment (mean: 2L, $8662 vs $5146; 3L, $11,339 vs $8748). During the 30-day end-of-life period, the mean total all-cause cost was $27,943.

Conclusions: Higher total all-cause PPPM costs were observed during the 3L than the 2L phase in r/mCC systemic treatment. Higher inpatient all-cause PPPM costs were observed during the off-treatment periods. Treatments that reduce the risk of or delay progression from 2L r/mCC may offer the opportunity to lower monthly costs.