OBJECTIVES

To measure the potential reduction in relapsed metastatic breast cancer cases due to the introduction of pertuzumab+trastuzumab (PH) for treating HER2+ early breast cancer patients in Argentina.

METHODS

Using an epidemiology model, we estimated the reduction in HER2+ mBC cases when treating HER2+ patients with PH in the adjuvant setting. Age-specific BC incidence rates from GLOBOCAN were applied to INDEC (National Institute of Statistics and Census) population estimates and projections for Argentina to determine BC incidence estimates over time. Staging distribution of HER2 and hormone receptor (HR) status data were estimated using institutional surveys, databases and published literature sources. We applied the disease-free survival (DFS) curves of trastuzumab (H) and PH regimes and estimates of local uptake rates for quantifying, the prevention in relapsing cases of HE2+ eBC to mBC over a 10-year period after H launch, and the additional impact of PH 10 and 20 years after its introduction into Argentinean population. DFS estimates for H were derived from the BCIRG-006 and NSABP studies with incremental benefit of PH over H based on the APHINITY study. Different treatment schemes rates over time were estimated using local HER2+ BC Patients Surveys. Model outputs for HER2+ eBC node positive (N+) and HER2+ eBC HR-negative (HR-) subgroups were provided.

RESULTS

Among HER2+ eBC N+ patients, the number of mBC cases projected to be prevented in the Argentinian population is 429 over 20 years (a 15% reduction), and 159 over 10 years (a 12% reduction). For HER2+ eBC HR-, the number of mBC cases projected to be prevented in this population is 278 over 20 years (a 15% reduction), and 94 over 10 years (a 10% reduction).

CONCLUSIONS

Early treatment with PH can lead to further reductions in HER2+ mBC incidence over the long-term and may translate into significant cost savings in Argentina.