SHR-A1811 for HER2-positive Breast Cancer With Suboptimal Neoadjuvant Response

Inclusion Criteria: * 1.Female patients with newly diagnosed breast cancer aged 18 to 70 years old; * 2.Early or locally advanced HER2-positive invasive breast cancer; * 3.Known hormone receptor status; * 4.ECOG score of 0-1; * 5.Patients who were determined by the researchers to have poor therapeutic effect after 4 cycles of neoadjuvant therapy; * 6.Organ function levels must meet the following requirements: * 7.Women of childbearing age must undergo a serum pregnancy test within 7 days before enrollment, with a negative result, and be willing to use a medically approved highly effective contraceptive method during the study and within 3 months after the last administration of the study drug. * 8.The subjects voluntarily participate in this study and sign the informed consent form. Exclusion Criteria: * 1\. Patients with metastatic or bilateral breast cancer, or inflammatory breast cancer * 2\. Patients with grade 3 or higher thrombocytopenia during previous treatment, or grade 3 or higher nausea and vomiting despite primary prevention * 3\. History of other malignant tumors (except cured carcinoma in situ of the cervix, basal cell carcinoma, etc.) and related treatment history * 4\. Patients who received major non-breast cancer surgery within 4 weeks before enrollment and have not recovered (except biopsy and PICC) * 5\. Autoimmune diseases (except special cases such as hypothyroidism and stable type 1 diabetes) * 6\. Interstitial lung disease, non-infectious pneumonia, uncontrolled systemic diseases * 7\. History of or planned administration of live attenuated vaccines within 28 days * 8\. HIV infection, active hepatitis (hepatitis B, hepatitis C, etc.), autoimmune hepatitis * 9\. Severe infection within 4 weeks, CTCAE grade ≥ 2 active infection within 2 weeks (except neoplastic fever), or evidence of active tuberculosis within 1 year * 10\. History of allogeneic bone marrow or solid organ transplantation * 11\. Peripheral neuropathy of grade ≥ 2 * 12\. Severe heart diseases * 13\. Receipt of systemic immunostimulant therapy within 4 weeks * 14\. Receipt of systemic immunosuppressant therapy within 2 weeks (except local or physiological dose of hormones) * 15\. Allergy to study drugs/excipients, or history of severe allergic reaction to other monoclonal antibodies * 16\. Pregnant or lactating women; fertile women with positive pregnancy test or unwilling to take effective contraception throughout the trial * 17\. History of neurological/psychiatric disorders , or history of substance abuse, alcoholism, or drug addiction * 18\. Other circumstances deemed unsuitable for enrollment by the researcher