PCN62 Budget IMPACT Analysis of Trastuzumab Emtansine for Residual Invasive HER2-Positive Breast Cancer in Argentina

Abstract

To assess the 10 years-evolution of the annual budget impact of trastuzumab emtansine (T-DM1) compared with trastuzumab to the treatment of patients with HER2-positive early breast cancer and residual invasive disease at surgery, after completion of neoadjuvant chemotherapy plus HER2-targeted therapy from the whole health system perspective in Argentina. A budget impact model was first developed. Age-specific Her2-positive incidence rates published by GLOBOCAN were applied to Argentinian population estimates to determine its annual potential patients. Extrapolation of Kaplan-Meier curves, assuming a lognormal distribution, was used to project the number of relapses avoided by the adoption of T-DM1, and the treatment durations in both adjuvant and metastatic settings. Incremental benefit of T-DM1 was based on the Katherine study. Drug acquisition costs were calculated using publicly available prices and resource usage rates were estimated by conducting a Delphi Panel. Unitary costs were extracted out of the Unit Costs Database. Total Budget Impact is shown in US Dollars using the official exchange rate. The annual Budget Impact from the T-DM1 arm increased from $9,05 MM to $41,58 MM in 10 years compared with an increase from $4,1 MM to $40,51 MM in the Trastuzumab arm. The proportion of the metastatic setting direct costs, presented as percentages of the total variation, ranged from 2% to 44% in the T-DM1 arm and from 9% to 76% in the comparator arm. This analysis shows that purchase and monitoring costs of T-DM1 compared with trastuzumab tend to equate at a 10- year time horizon. This may be related to a lower relapse rate in the T-DM1 group. Although the driver of costs at the beginning of the analysis is related to the acquisition costs, relapse- related costs in the trastuzumab group represent a higher proportion of the total costs of care at the end of the analysis.