Out-of-Pocket Costs for Tyrosine Kinase Inhibitors and Patient Outcomes in <i>EGFR</i>- and <i>ALK</i>-Positive Advanced Non-Small-Cell Lung Cancer.

Abstract

We investigated the association of out-of-pocket (OOP) costs for tyrosine kinase inhibitors (TKIs) with overall survival (OS) in epidermal growth factor receptor (<i>EGFR</i>)- and anaplastic lymphoma kinase (<i>ALK</i>)-positive advanced non-small-cell lung cancer (NSCLC). We secondarily investigated associations of TKI OOP costs with TKI adherence, duration of therapy (DOT), and TKI discontinuation. We used the Hutchinson Institute for Cancer Outcomes Research registry-claims database to identify patients with stage IV <i>EGFR</i>- or <i>ALK</i>-positive NSCLC; ≥ 1 claims for <i>EGFR</i> or <i>ALK</i> TKIs; and ≥ 3-month survival from TKI initiation. We estimated the average monthly TKI OOP costs per patient up to 3 months from TKI initiation, categorizing patients into quartiles of TKI OOP costs (Q1 < Q2 < Q3 < Q4). We conducted landmark analysis at 3 months from TKI initiation to compare Q1-3 <i>v</i> Q4 TKI OOP costs with respect to OS, TKI DOT, TKI adherence, and TKI discontinuation. Seventy-eight and twenty-seven patients comprised the Q1-3 and Q4 groups, respectively. Median monthly TKI OOP costs were $1,431 (Q1-3) <i>v</i> $2,888 (Q4). Compared with Q1-3, Q4 patients had inferior OS (adjusted hazard ratio [HR], 1.85; [95% CI, 1.11 to 3.10], similar TKI DOT (adjusted HR, 1.06; 95% CI, 0.53 to 2.15), decreased TKI adherence (adjusted odds ratio [OR], 0.28; 95% CI, 0.10 to 0.76), and higher TKI discontinuation rate (adjusted OR, 8.75; 95% CI, 2.59 to 29.52). Among patients with advanced <i>EGFR</i>- and <i>ALK</i>-positive NSCLC, higher TKI OOP costs are associated with decreased TKI adherence, a higher likelihood of TKI discontinuation, and inferior survival.