The trial included screening period (4 weeks) and treatment period (4 treatment cycles, at least 12 weeks).

A multicenter, randomized, double-blind, positive drug parallel control design was used. The trial included screening period (4 weeks) and treatment period (4 treatment cycles, at least 12 weeks). All eligible subjects were randomly divided into experimental group (hs627 treatment group) and control group (pertuzumab) treatment group. After 4 treatment cycles, the subjects arranged surgical treatment, and then conducted the last visit.

Inclusion Criteria:

• Histologically confirmed invasive breast carcinoma with a primary tumor size of more than (>) 2 centimeters (cm) by standard local assessment technique；
• Breast cancer stage at presentation: early-stage (T2-3, N0-1, M0), locally advanced (T2-3, N2-3,M0 or T4a-c, any N, M0), or infl ammatory (T4d, any N,M0)；
• Known hormone receptor status (estrogen receptor and/or progesterone receptor)；
• HER2 positive (HER2+++ by IHC or ISH+).
• Baseline left ventricular ejection fracture >= 55% measured by echocardiography (preferred) or multiple gated acquisition scan；
• Normalities in liver, kidney or hematologic function laboratory tests immediately prior to randomization;
• Absolute value of neutrophils ≥ 1.5 × 109 / L;
• Platelet ≥ 90×109 / L;
• Hemoglobin ≥ 90g / L;
• Serum creatinine≤ 1.5 times the upper limit of normal (ULN);
• Serum total bilirubin≤1.5 times ULN (except for Gilbert syndrome);
• Aspartate aminotransferase (AST) and / or alanine aminotransferase (ALT) ≤ 1.5-fold ULN;
• International normalized ratio (INR), activated partial prothrombin time (APTT) ≤ 1.5 times ULN.
• ECOG≤1；

Exclusion Criteria:

• Stage IV metastatic ;
• Bilateral breast cancer;
• Previous anti-cancer therapy or radiotherapy for any malignancy;
• History of other malignancy within 5 years, except for appropriately-treated carcinoma in Cervical carcinoma in situ, basal cell carcinoma or squamous cell skin cancer;
• Serious cardiac illness or medical condition;
• HIV antibody positive; HCV antibody positive and HCV RNA positive; HBcAb or HBsAg positive, and HBV DNA positive;
• Sensitivity to any of the study medications, any of the ingredients or excipients of these medications;
• Known mental history had poor compliance;
• Known to have drug abusers;
• Concurrent anti-cancer treatment in another investigational trial, including hormone therapy, bisphosphonate therapy, or immunotherapy;
• Needed intravenous antibiotic treatment due to infection within 7 days before random enrollment;
• Major surgical procedure unrelated to breast cancer within 4 weeks prior to randomization or expected to perform major surgery during the trial period;
• Premenopausal women (menopause is defined as non treatment induced menopause≥12 months) or without surgical sterilization (e.g., ovariectomy and / or uterus): refuse to take one or more effective contraceptive measures during treatment and at least 6 months after the last study treatment; blood pregnancy test is positive; pregnant or lactating women; Considered unsuitable for the study or may not be able to complete the trial due to other reasons.