Breast cancer (BC) is the most common type of cancer in women and one of the leading causes of death among women worldwide, including our country. According to the World Health Organization, over 11,000,000 women with diagnosed BC receive care and treatment worldwide. Each year approximately 1,200,000 new cases of breast cancer are registered and more than 500,000 women die, and it is estimated that the incidents will increase up to 1,450,000. The objective of this study was to determine a treatment regimen (pertuzumab+trastuzumab+docetaxel or placebo+trastuzumab+docetaxel) more advantageous from the pharmacoeconomic point of view, used in the treatment of HER2+ metastatic breast cancer (mBC), on the basis of comparison of costeffectiveness ratio, safety and life quality. The results of the cost-effectiveness analysis showed that cost-effectiveness ratios (effectiveness criterion – Life Years Gained, LYG) were as follows (over a period of 25 years: 1,823,530 rubles in the pertuzumab+trastuzumab+docetaxel group and 587,120 rubles in the placebo+trastuzumab+docetaxel group. The incremental costeffectiveness ratio for the health technologies compared was 8,150,535 rubles/LYG. The results of the cost-utility analysis showed that the cost-utility ratios (utility criterion – Quality Adjusted Life Years, QALY) were as follows (over a period of 25 years): 2,716,738 rubles in the pertuzumab+trastuzumab+docetaxel group and 908,787 rubles in the placebo+trastuzumab+docetaxel group. The incremental cost-effectiveness ratio for the health technologies compared was 10,187,748 rubles/QALY. The results of the budget impact analysis demonstrated that for the Perjeta-trastuzumab-docetaxel treatment regimen, the difference in the required budgetary funds was 5,711,668 rubles in comparison with the placebo-trastuzumab-docetaxel treatment regimen per treatment of one patient with BC (over a period of 25 years).