Long Term Efficacy of Pertuzumab For HER2+ Metastasic Breast Cancer Ecuadorian Population

OBJECTIVES: assess long-term efficacy of Pertuzumab in treatment of metastasic HER2+ breast cancer in Ecuador. METHODS: Globocan data was used to calculate HER2+ metastasic population on Ecuador and data from Cleopatra clinical trial and epidemiological data from the tumor registry at Munich were used to perform an overall survival (OS) and progression-free survival (PFS) extrapolation of 5 and 10 years. The probability of being alive or remaining in PFS was determined by OS or PFS probabilities obtained from CLEOPATRA study Kaplan-Meier estimates or parametric function that was fitted to data. Extrapolation beyond clinical follow-up period was performed by fitting parametric distribution to the observed OS and PFS times from the study period of the trial. This was done independently for each treatment arm (assuming independent shape). With results obtained we compared the number of Ecuadorian patients treated with current standard therapy Trastuzumab that will be still alive in 10 years against the number of Ecuadorian patients that will be still alive in 10 years if Pertuzumab was new standard treatment for metastasic HER2+ breast cancer. RESULTS: With annual metastasic HER2+ breast cancer incidence of 3 per 100,000 inhabitants Ecuador will have 580 women suffering from metastasic HER2+ breast cancer in 10 years. Considering current therapy, of the 580 women treated in 10 years, at the 10th year 278 women will be still alive and 138 won't have progressed. With Pertuzumab, of the 580 women treated in 10 years, at the 10th year 340 women will be still alive and 189 won't have progressed. Changing from Trastuzumab to Pertuzumab would save 62 more women and would avoid the progression of 51 more women in ten years. CONCLUSIONS: Pertuzumab could potentially change long-term outcome of HER2+ metastasic breast cancer in Ecuador by saving 24 more women in 5 years and 62 more women in 10 years.