P1.16-30 Impact of Patient TKI Copayments on Insurance Expenditure in Advanced EGFR or ALK Positive Non-Small Cell Lung Cancer (NSCLC)

Abstract

To influence treatment choice and control expenditures, insurance plans impose cost sharing policies for expensive oral tyrosine kinase inhibitors (TKIs). We evaluated the effect of patient TKI copayments on insurance expenditures among patients with EGFR and ALK positive advanced NSCLC receiving TKIs. We identified EGFR+ and ALK+ NSCLC patients in the Washington State SEER registry using natural language processing on registry pathology reports, followed by manual confirmation of molecular test results. We linked registry records with commercial and Medicare claims. Eligible patients had stage IV NSCLC diagnosed between 01/01/2010 and 12/31/2016, EGFR exon 19 deletions or L858R mutations, or ALK + by FISH, ≥ 12 months of insurance enrollment, survival of ≥6 months, and ≥ 1 pharmacy claims for EGFR or ALK TKIs with FDA approval in the study period. We estimated monthly TKI copayments by subtracting the drug amount paid from the amount allowed by insurance in pharmacy claims. We used claims to calculate lifetime total and drug costs from the insurance perspective. Covariates included sociodemographic characteristics, insurance type, comorbidity, mutation type, and receipt of chemotherapy and immunotherapy. We used generalized linear models with gamma family and log link to estimate the adjusted effect of TKI copayment of $0 vs. above $0 on insurer expenditures in 2016 US dollars. Of 103 eligible patients, median age was 69; 66% were female; 72% were White, median household income was $69,951; 54% had Medicare, 85% were EGFR+, and 51% received chemotherapy or immunotherapy. Mean monthly TKI copayment was $312 (range= $0 to $5,913). Mean total and drug reimbursements were $234,294 and $114,253. Table 1 shows the adjusted effect of TKI copayments on insurance expenditures. Higher TKI copayments were not associated with lower insurance expenditures. Eliminating TKI copayments would reduce patient financial burden and not adversely impact insurer spending.Table 1Effect of Patient TKI Copayments on Insurance Expenditures, Adjusted for Age, Race, Comorbidity, Insurance Type, Mutation Type, Receipt of Chemotherapy and Immunotherapy (EGFR TKIs: erlotinib, gefitinib, afatinib, osimertinib; ALK TKIs: crizotinib, alectinib, ceritinib, brigatinib).TKI Copayment (n=103)Adjusted Mean Total Expenditure (95% CI)P valueAdjusted Mean Drug Expenditure (95% CI)P value$0 (n=82)$230,989 ($188,958; $273,019)Ref.$110,171 ($88,150; $132,194)Ref.Above $0 (n=21)$264,963 ($182,424; $347,502)0.44$132,707 ($83,206; $182,208)0.38 Open table in a new tab