Economic Burden of Early Treatment Failure with PD-1 Inhibitor Immunotherapy in Metastatic Non-Small Cell Lung Cancer

Abstract

Metastatic non-small cell lung cancer (mNSCLC) remains a major clinical and economic burden, and early treatment failure (ETF) after first-line PD-1 inhibitor therapy may identify patients with poor downstream cost outcomes. This retrospective cohort study used Merative MarketScan Commercial Claims and Medicare Supplemental data from 2019-2023 to evaluate ETF among adults with mNSCLC initiating first-line pembrolizumab, nivolumab, or cemiplimab. A 90-day landmark design was used, and ETF was defined as early discontinuation of the indexed PD-1 inhibitor, initiation of a new systemic anticancer therapy not included in the original regimen, or both. Survival-adjusted cumulative costs were estimated using overlap-weighted Kaplan-Meier sample average methods, and survival, per-patient-per-month (PPPM) cost, and utilization outcomes were analyzed using overlap-weighted, covariate-adjusted models. Among 1,873 patients in the analytic cohort, 720 were classified as ETF and 1,153 as No ETF. ETF was associated with worse overall survival after the landmark (HR, 2.17; 95% CI, 1.81 to 2.60). At 365 days, survival-adjusted cumulative costs were higher in patients with No ETF than ETF ($278,151 vs $177,502; difference, -$100,649; 95% CI, -$120,309 to -$81,361). Total PPPM cost was also lower in ETF than No ETF ($20,484 vs $25,734; difference, -$5,250; 95% CI, -$8,335 to -$3,133). ETF was associated with higher inpatient admissions and inpatient days. Overall, ETF was associated with worse survival and greater inpatient burden, whereas patients without ETF accumulated higher healthcare costs over follow-up.