BACKGROUND: Afatinib is 1 of 3 tyrosine kinase inhibitors approved in the United States for the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors have epidermal growth factor receptor (EGFR) exon 19 deletions (del19) or exon 21 (L858R) substitution mutations. In clinical trials, afatinib has demonstrated improvement in progression-free survival versus standard chemotherapy and gefitinib.
OBJECTIVE: To analyze the impact of increases in afatinib treatment share on the cost and health outcomes in a commercial health plan in the United States.
METHODS: A decision model was developed to evaluate the budget impact of increases in afatinib share for the first-line treatment of patients with metastatic NSCLC with EGFR del19 or L858R substitution mutations over a 5-year time horizon. The model compared the total annual costs for a health plan with 1 million covered lives in a scenario in which afatinib share increased 5 percentage points annually to one in which all treatment shares remained constant over time. The number of patients eligible for treatment was estimated using published incidence data. Therapies included in the model were afatinib, erlotinib, gefitinib, and the chemotherapy doublet, pemetrexed in combination with cisplatin. The mean time spent by patients in progression-free and progressive disease states was based on survival data from clinical trials and a network meta-analysis. Therapy-related costs included monthly drug acquisition and administration costs and costs of managing adverse reactions. Disease management costs were also assessed in the model. Scenario analyses were performed to assess alternative scenarios of afatinib treatment share. Additionally, a one-way sensitivity analysis was performed to test the robustness of the model, given parameter uncertainty.
RESULTS: Using the base-case parameter assumptions and a 5-percentage-point annual increase in afatinib treatment share, we estimated the total budget increases in years 1 through 5 to be $1,606, $65,542, $140,564, $209,272, and $303,368, respectively. These budget increases translated to per-member-per-month increases ranging from $0.00 to $0.03 in years 1 to 5. The increase in afatinib use resulted in the proportion of the treated population (134 patients treated over 5 years) remaining in progression-free disease increasing from 23.7% to 26.2% at the end of year 5, versus if afatinib treatment share had stayed constant.
CONCLUSIONS: Increasing the treatment share of afatinib in a health plan for the first-line treatment of NSCLC with EGFR del19 or L858R mutations was estimated to increase the proportion of treated patients remaining in progression-free disease, while having small budget impact to the health plan.
