Cost evaluation of adjunctive osimertinib use in resected epidermal growth factor receptor-positive non-small cell lung cancer.

Abstract

8525 Background: About 30% of patients with epidermal growth factor receptor positive (EGFR+) non small cell lung cancer (NSCLC) are eligible for surgical resection. Osimertinib, a first line therapy for advanced EGFR+ NSCLC (stages 1B, 2, 3A), has shown clinical efficacy compared to placebo as an adjunctive therapy post resection. We evaluated the cost effectiveness/utility of this regimen. Methods: A two health state Markov model was built (disease free vs. disease recurrence or death). Disease free survival (DFS) curves were digitized and fitted to exponential function. 3 year timeline as patients received osimertinib for 3 years in published data. US payer perspective and 3% discount rate were applied. Drug costs were per Redbook whole acquisition cost and monitoring costs were from published data (US$ 2020). No adverse events > 5% were reported hence none were included. Life years (LY) and quality adjusted life years (QALY) were estimated for each stage. Incremental cost-effectiveness and utility ratios (ICER/ICUR) for LY and QALY gained were estimated in base case (BCA) and probabilistic sensitivity analyses (PSA). Results: Shown in the table are BCA and (PSA) results. Using LY as outcome, for stage 1B, incremental DFSLY of 0.40 (0.39) and incremental cost of $500,782 ($501,034) yielded an ICER/DFSLYG of ̃$1.3 million (M) (̃$1.2 M). For stage 2, incremental DFSLY of 0.79 (0.79) and incremental cost of $503,144 ($503,092) resulted in an ICER/DFSLYG of $636,913 ($638,278). For stage 3A, incremental of DFSLY of 0.18 (0.07) and incremental cost of $322,356 ($293,377) yielded an ICER/DFSLYG of ̃$1.2 M (̃1.2 M). The incremental costs are the same for QALY outcomes. Using QALY as outcome, for stage 1B, incremental of DFSQALY of 0.26 (0.27) yielded an ICUR/DFSQALY of ̃$1.9 M. In stage 2, incremental DFSQALY of 0.53 (0.53) resulted in an ICUR/DFSQALY of $950,616 ($952,654). For stage 1C, incremental DFSQALY of 0.18 (0.07) yielded an ICUR/DFSQALY of ̃$1.8 M (̃$3.7 M). Conclusions: The ICERs and ICURs indicate that cost effectiveness varies markedly across stages of disease. Stage 2 showed the lowest cost to outcome association. In general, the cost burden of adjunctive maintenance therapy with osimertinib in resected EGFR+ NSCLC is substantial relative to the observed clinical benefit. The incremental benefit of osimertinib in stage 2b is more evident than the ones in 1B and 3A.[Table: see text]