P3.02b-010 Urine Detection of EGFR T790M Mutation in Non-Small-Cell Lung Cancer: An Outcomes and Total Cost of Care Analysis: Topic: EGFR Biomarkers

Abstract

Third-generation tyrosine kinase inhibitors (3rd-TKIs) have proven effective in patients with EGFR T790M who progress on prior EGFR TKI therapy. Median progression-free survival (PFS) on a 3rd-TKI was 9-10 months for T790M+ patients compared to 2-4 months for T790M- patients. PFS is similar regardless of the specimen used to assess T790M (tissue, plasma, or urine). Using simulation analytics, the primary study aim was to assess the cost effectiveness of a urine-testing strategy (UTS) versus a tissue-testing strategy (TTS) for T790M detection in patients with EGFR-positive lung adenocarcinoma and progression on prior TKI therapy. Analytics followed International Society for Pharmacoeconomics and Outcomes Research (ISPOR) and Society for Medical Decision Making (SMDM) guidelines for Good Modeling Practices and Consolidated Health Economic Evaluation Reporting Standards (CHEERS) for reporting findings. Outcomes and economic implications were assessed from the perspective of a third-party US payer, stratified by government versus commercial fee rates. Endpoints were PFS, overall survival (OS), direct medical resources used (biopsies, chemotherapy, post-progression) and related costs. Data sources were published reports of randomized drug trials and current data, which includes accuracy results of tissue versus urine testing (Trovagene, San Diego, CA), Medicare fee schedules, and available adjustments for fees in commercial markets. A state-transition analysis and Markov model tracked patients from stable disease, progression, and to death. Full univariate and multivariate sensitivity analyses were performed to assess the robustness of findings and factors that most influenced outcomes and costs. Median PFS after treatment with 3rd-TKI was 3.4 months if tumor testing is T790M- versus 9.7 months if T790M+. Because urine testing can be used in patients for whom biopsy cannot be performed or when tissue testing reveals indeterminate results, PFS and OS were slightly increased using the UTS. UTS resulted in avoidance of a biopsy procedure, potential complications, and tissue-based molecular testing in approximately 48% of patients, leading to a 2- to 10-fold total cost savings relative to the unit cost for a urine test. Within the robust variations in input parameters, the cost of a biopsy procedure/complications and tissue-based molecular testing were the most influential factors. UTS is a dominant scenario to TTS by saving costs and improving patient experience (e.g., PFS/OS, and reduction in biopsy related complications). This result is based on LEVEL I evidence from a large, randomized trial that showed PFS is similar among patients regardless of urine versus tissue testing for T790M mutation status.