A Study of SHR-A1811 as Neoadjuvant Treatment for Patients With HR-Positive, Low HER2 Expression Breast Cancer

This prospective, single-arm study is being conducted to evaluate the efficacy and safety of SHR-A1811 for early-stage or locally advanced breast cancer patients with HR-Positive, Low HER2 Expression. Subjects will receive the neoadjuvant therapy of SHR-A1811 for eight cycles, and then undergo surgery within 4 weeks after neoadjuvant therapy. The follow-up visit will last for at least 5 years.

Inclusion criteria

• 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;
• Normal organ and bone marrow function;
• Patients of childbearing age must consent to use highly effective contraception for 7 months from the start of study screening until the last study medication and agree not to breastfeeding;
• Patients voluntarily joined the study and signed informed consent;

Exclusion criteria

• 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;
• Clinically significant pulmonary or cardiovascular disease;
• Failure to swallow, chronic diarrhea, intestinal obstruction, or presence of other factors affecting drug administration and absorption;
• Known to be allergic to any study drug or any of its excipients;
• History of immunodeficiency, including HIV-positive, or other acquired or congenital immunodeficiency diseases, or history of organ transplantation;
• Pregnant and lactating women;
• Patients with serious concomitant diseases or other comorbidities that will interfere with the planned treatment, or any other condition that is not suitable for participation assessed by investigator.