Short-term Sintilimab in Combination With Taxane and Carboplatin for Neoadjuvant Therapy in Triple-negative Breast Cancer (NeoSTEP)

Inclusion Criteria: Age: 18-70 years, female; Unilateral, invasive, primary breast cancer, T≥1cm, cN0-3, M0; Immunohistochemistry(IHC): ER, PR<10%; HER-2 IHC "0", OR IHC "+", OR IHC "++" AND fluorescence in situ hybridization (FISH) negative; At least one measurable lesion according to RECIST V1.1; Newly or recently-collected core needle biopsy specimen of the primary lesion available for PD-L1 status determination; ECOG score 0 or 1 within 10 days prior to drug administration; Currently not pregnant or breastfeeding, and meet at least one of the following conditions: NOT women of childbearing potential (WOCBPs). WOCBPs that strictly adopt contraceptive measures during treatment and within at least 6 months after last drug administration. Organs well-functioned according to laboratory examination and imaging; Having good compliance with treatment plans, being capable of understanding the research process, and having signed a written informed consent. Exclusion Criteria: Bilateral invasive breast cancer or metastatic (Stage IV) breast cancer; With severe cardiovascular conditions: Myocardial infarction, acute coronary syndrome or PCI/CABG within 6 months; Current NYHA II-IV congestive heart failure (CHF) or past history of NYHA III-IV CHF. Immunodeficiency, or undergoing systemic steroid therapy or any form of immunosuppressive therapy within 7 days prior to drug administration; Active autoimmune diseases requiring systemic treatment within the past 2 years; Known history of active tuberculosis caused by Bacillus Tuberculosis; History of non infectious pneumonia requiring steroid treatment, or active pneumonia of all types; Severe systemic infections, or other serious illnesses; History of other malignant tumors within the past 5 years, except cured cervical carcinoma in situ and non-melanoma skin cancer; Known history of human immunodeficiency virus (HIV) infection; Active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection; Known allergy or intolerance to therapeutic drugs or their excipients; History of receiving cytotoxic chemotherapy, endocrine therapy, biological therapy or radiation therapy for any reason; History of receiving anti PD-1, anti PD-L1, or anti PD-L2 drugs; or targeted drugs that act on stimulating or co-inhibitory T cell receptors (CTLA-4, OX 40, CD137 etc.); Enrolled in a study of an investigational drug/instrument and given intervention within 4 weeks prior to drug administration for regular drugs/instruments and within 12 months for anticancer or anti-proliferative drugs/instruments; Live vaccine (including but not limited to the following: measles, mumps, rubella, chickenpox/shingles, yellow fever, rabies, BCG, typhoid vaccines, and nasal influenza vaccines such as FluMist®) inoculation within 30 days prior to drug administration; History of mental illness or drug abuse that may affect compliance with trial requirements; During pregnancy or breastfeeding, or WOCABs that refuse to adopt strict contraceptive measures; Deemed to be not appropriate for participating in this study by researchers.