Presentation (CTI)

OBJECTIVES: Tyrosine kinase inhibitors (TKIs) targeting EGFR have become the standard first-line treatment for patients with EGFR-mutated non-small cell lung cancer (NSCLC), with their use steadily increasing, particularly following the reimbursement of third generation TKIs in South Korea. Understanding the characteristics and healthcare expenditures of TKI users is essential for optimizing patient management and informing healthcare policy decisions.
METHODS: We conducted a retrospective cross-sectional study using 2018-2019 data from Health Insurance Review and Assessment Service-National Patient Sample. Based on a prevalence-based approach, patients with EGFR-mutated NSCLC were defined as those diagnosed with lung cancer (ICD-10: C34) and prescribed EGFR-TKIs (gefitinib, erlotinib, afatinib, or osimertinib). Clinical characteristics included age group, sex, metastasis sites, comorbidities, and Charlson Comorbidity Index (CCI) scores. Healthcare costs were assessed as all-cause and disease-related costs, as well as drug costs per patient per year (PPPY). Descriptive analyses were performed using SAS version 9.4.
RESULTS: Among 461 patients, TKI prescriptions were gefitinib (47.1%), afatinib (27.1%), erlotinib (17.4%), and osimertinib (8.5%), with differences in distribution (aSD 0.236-0.956). A majority were female (62.9%) and aged ≥ 65 years (57.3%), with partial imbalance among TKIs. The most common metastasis site was brain (43.2%), with well-balanced characteristics between TKIs (aSD 0.044-0.138). The mean CCI score was 3.74 (SD 3.54). The median all-cause medical cost (PPPY) was 7,956 USD (IQR 3,686-15,419), with inpatient 6,153 USD and outpatient 2,826 USD. The costmedian disease-related inpatient cost (PPPY) was 5,639 USD, all-cause drug cost was 7,907 USD, and disease-related drug cost was 6,419 USD. The highest expenditures were observed in patients receiving osimertinib, with all-cause medical (13,251 USD) and drug costs (39,239 USD), as well as disease-related inpatient (7,934 USD) and drug costs (37,398 USD).
CONCLUSIONS: Among TKIs, characteristics were partially balanced, and drug costs were the major driver of healthcare expenditure, especially for osimertinib.