The goal of this study is to compare the efficacy and safety of BCD-178 and Perjeta as neoadjuvant therapy for HER2-positive breast cancer.

Subjects with histologically confirmed diagnosis of HER2-positive invasive breast cancer (stage II-III, tumor size > 2 cm), with no estrogen (ER) and progesterone (PR) receptors will be randomized to one of two treatment groups (BCD-178 group or Perjeta group) in a 1:1 ratio.

Inclusion Criteria:

• Signed informed consent ;
• Histologically confirmed diagnosis of invasive breast cancer;
• Disease stage cT2-cT4, cN0-cN3, cM0;
• Positive HER2 expression, negative estrogen and progesterone receptor expression;
• ECOG score 0-1;
• Adequate organ function;
• Baseline LVEF ≥ 55%, as measured with the standard procedure;
• Consent of women of childbearing potential to use highly effective methods of contraception, starting from the signing of the informed consent form, throughout the study and for 6 months after receiving the last dose of the product.

Exclusion Criteria:

• Stage IV (metastatic) breast cancer;
• A history of any systemic therapy for breast cancer;
• Concomitant diseases and/or conditions that significantly increase the risk of adverse events during the study;
• Pregnancy or breastfeeding, as well as pregnancy planning throughout the study and for 6 months after receiving the last dose of the product;
• Hypersensitivity or allergy to any of the components of BCD-178, Perjeta, trastuzumab, carboplatin, and docetaxel.