BACKGROUND: Neratinib, an oral, irreversible tyrosine kinase inhibitor of multiple human epidermal growth factor receptors (HERs), is indicated for the extended adjuvant treatment of adult patients with HER2-positive early-stage breast cancer (eBC) following adjuvant trastuzumab-based therapy in the United States (US). Greater efficacy of neratinib compared to placebo has been seen in patients with hormone receptor-positive (HR+) breast cancer who initiated neratinib within 1 year of completing trastuzumab (HR+/≤ 1-year) and for patients who did not achieve a pathologic complete response after neoadjuvant therapy (HR+/≤ 1-year/no pCR).
OBJECTIVE: This study explored the cost-effectiveness of neratinib versus placebo from a US third-party payer perspective for both the HR+/≤ 1-year and HR+/≤ 1-year/no pCR populations.
METHODS: Lifetime costs and health outcomes of neratinib and placebo were modeled with a 5-health-state Markov model representing the primary stages of disease in eBC. Overall survival was modeled based on a combination of post–distant recurrence survival (PDRS) and general mortality. Extrapolation of invasive disease-free survival, PDRS, the proportion of local and distant recurrence, and number of adverse events were derived from the ExteNET clinical trial. Costs were calculated based on drug acquisition, administration, and monitoring costs, as well as treatment costs for adverse events and health state–related medical resource use (2020 USD). Quality-adjusted life-years (QALYs) were estimated per health state, and disutilities were applied per adverse event independent of treatment. Sensitivity and scenario analyses were performed to investigate the robustness of the results.
RESULTS: Neratinib treatment resulted in improved treatment outcomes compared with placebo of 0.89 QALYs gained for the HR+/≤ 1-year population and 1.18 QALYs gained for the HR+/≤ 1-year/no pCR population. The base-case analysis showed that, compared with placebo, neratinib treatment resulted in a cost per QALY gained of $62,172 for the HR+/≤ 1-year population. For the HR+/≤ 1-year/no pCR population, the cost per QALY gained was improved to $29,500 due to the increased efficacy of neratinib in that population. The results were robust across multiple sensitivity and scenario analyses, with incremental cost-effectiveness ratios below $90,000.
CONCLUSIONS: The current analysis shows that neratinib is a cost-effective therapy for both the HR+/≤ 1-year and HR+/≤ 1-year/no pCR population.
