HR-positive breast cancers accounts for about 50% to 60% of all breast cancer patients. Neoadjuvant Chemotherapy is the core treatment mode for this type of breast cancer, and endocrine therapy can be used in some low-risk patients. However, the pathological complete response (pCR) rate obtained is low. HER2 is an important prognostic indicator and therapeutic target for breast cancer. Nearly 60% of HR-positive breast cancers have low expression of HER2, and antibody-drug conjugates (ADC) targeting HER2 may achieve better efficacy in this subtype.
Patients aged 18 to 70 years old (inclusive);
Treatment-naive patients with clinically confirmed T2-T3, any nodal status and M0;
HR-positive, HER2 low expression, the expression of Ki-67 exceed 14% invasive breast cancer confirmed by histology or cytology;
ECOG performance status of 0-1;
Patients have evidence of metastatic breast cancer, or inflammatory breast cancer;
Patients previously received antineoplastic therapy or radiotherapy for any malignancy, excluding cured malignancies such as cervical carcinoma in situ, basal cell carcinoma, or squamous carcinoma;
Patients received any other anti-tumor therapy at the same time, including endocrine therapy, bisphosphonates or immunotherapy;
Patients have major surgical procedures unrelated to breast cancer within 4 weeks before the first medication, or not fully recovered from surgical procedures;