Economic Burden of Checkpoint Inhibitor Immunotherapy for the Treatment of Non-Small Cell Lung Cancer in US Clinical Practice.

PURPOSE: The efficacy of checkpoint inhibitor (CPI) immunotherapy in patients with non-small cell lung cancer (NSCLC) is limited by a lack of strongly predictive response markers, subjecting patients to potential underutilization of alternative effective treatments, increased risk for futile care, and unnecessary costs. Here, we characterize the extent to which basic molecular tumor-marker testing has been performed for NSCLC therapy selection in the United States, and compare medical resource utilization and costs in CPI-treated patients versus CPI-eligible patients treated with other therapies.
METHODS: We identified a cohort of CPI-treated patients with NSCLC and a propensity score-matched cohort of CPI-eligible patients with NSCLC treated with non-CPI therapies (3095 patients in each group), using US administrative claims data covering the pre- and postinitial FDA-approval period for nivolumab, pembrolizumab, and atezolizumab (October 2012 to September 2017). We describe the utilization of recommended baseline molecular testing for CPI selection (pre-index date for CPI or other anticancer therapy), including programmed death ligand 1 (PD-L1) immunohistochemistry, ALK rearrangement and EGFR mutation testing, and pre- and postindex treatment patterns. All-cause medical resource utilization and semiannual total reimbursement (costs) were compared between CPI-treated and non-CPI-treated patients.
FINDINGS: At baseline, in the propensity score-matched CPI- and non-CPI-treated patient cohorts, mean PD-L1 immunohistochemistry test utilization for CPI selection was moderate (0.6 vs 0.7 per patient, respectively). However, we observed much lower mean utilization of testing for EGFR mutations (0.1 vs 0.1 per patient) and ALK rearrangements (0.1 vs 0.2 per patient). Postindex, the use of both chemotherapy and ALK- and EGFR-targeted therapies were decreased in both cohorts. The CPI-treated group had significantly higher mean medical resource utilization in nearly all categories in the postindex period, and total per-patient semiannual costs, than did the CPI-eligible patients who received other therapies (141,537 vs 75,429 US dollars [USD]; P < 0.0001), driven by CPI drug reimbursement. Median (interquartile range) time on CPI was longest with pembrolizumab (113 [106-127] days), followed by nivolumab (105 [97-106] days) and atezolizumab (64 [50-85] days). Despite being associated with the lowest drug cost and the shortest treatment duration, atezolizumab was associated with the highest mean total per-patient semiannual costs (160,540 USD) compared with pembrolizumab (153,003 USD) and nivolumab (138,542 USD). IMPLICATIONS: The advent of CPI treatment for NSCLC has added substantial care-related costs for patients and payers, concurrent with underutilization of minimum recommended molecular testing for therapy selection. Broad uptake of panel-based comprehensive targeted-therapy and immunotherapy profiling can promote optimal treatment selection and sequencing, reduce the likelihood of futile treatment, and further improve patient outcomes.