Adebrelimab Combined With Dalpiciclib and Standard Endocrine Therapy for HR + / HER2- Breast Cancer

This single-center, open-label, single-arm clinical trial aims to evaluate the efficacy and safety of the neoadjuvant treatment with the PD-L1 inhibitor Adebrelimab in combination with the CDK4/6 inhibitor Dalpicicilib in combination with standard endocrine therapy, for stages II-III hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) breast cancer.

Inclusion criteria

• Postmenopausal women, aged ≥18 years;
• Postmenopausal patients and all patients in the screening period must one of the following:

• Previous bilateral oophorectomy, or aged ≥60 years;
• Aged <60 years, natural Postmenopausal status (defined as spontaneous cessation for at least 12 consecutive months without other pathological or physiological causes), E2 and FSH at the postmenopausal level;
• Histologically confirmed HR+/HER2- invasive breast cancer (specific definition: ER &gt;10% tumor cell positive is defined as ER positive, PR &gt;10% tumor cell positive is defined as PR positive, ER and/or PR positive is defined as HR positive; HER2 0-1+ or HER2 ++ but negative by FISH test, no amplification, defined as HER2 negative);
• Histologically confirmed invasive breast cancer, stage II-III breast cancer diagnosed based on AJCC cancer staging system (8th edition) ;
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1;
• According to the RECIST 1.1 standard, at least one measurable lesion exists;
• The main organs have basically normal functions and meet the following conditions:

• Bone marrow function: Hb≥90 g/L (no blood was transfused within 14 days); ANC≥1.5×109/L;PLT≥80×I09/L;
• Liver and kidney function: TBlL≤1.5×ULN; ALT and AST≤3×ULN; serum Cr≤1.5 ULN and creatinine clearance>50 ml/min (Cockcroft-Gault formula);
• Subjects voluntarily joined the study, signed informed consent, had good compliance, and cooperated with follow-up.

Exclusion criteria

• Previous use of CDK4/6 inhibitors or PD1/PD-L1 monoclonal antibody or concurrent treatment with any other antitumor therapy;
• Severe organ dysfunction;
• Inability to swallow,chronic diarrhea and intestinal obstruction,there are multiple factors that affect drug intake and absorption;
• Patients with known HBV or HCV infection active phase or HBV DNA≥500, or chronic phase with abnormal liver function;
• History of active autoimmune disease (such as interstitial pneumonia, colitis, hepatitis, pituitaritis, vasculitis, nephritis, hyperthyroidism, hypothyroidism, including but not limited to these diseases or syndromes)
• History of immunodeficiency, including HIV testing positive, or other acquired, congenital immunodeficiency diseases, or a history of organ transplantation and allogeneic bone marrow transplantation; History of interstitial lung disease (except radiation pneumonia without hormone therapy) and non-infectious pneumonia;
• History of any heart disease, including:1)medicated or clinically significant arrhythmia; 2) myocardial infarction; 3) heart failure; 4) any other cardiac disease judged by the investigator for the trial;
• Patients during pregnancy and lactation, women of childbearing age who refuse to take effective contraceptive measures during the study period;
• According to the discretion of the investigator, there are significant risks to patient safety or concomitant diseases affecting the patient&#39;s completion of the study (including but not limited to severe hypertension, severe diabetes, active infection);
• Have a clear history of neurological or psychiatric disorders, including epilepsy or dementia;
• Any condition deemed inappropriate for the patient&#39;s participation in this study by the investigator.