Mecapegfilgrastim for the Prevention of Dalpiciclib -Induced Neutropenia in Advanced Breast Cancer

Exclusion Criteria

• •1. Previous pathological diagnosis of HER2 positive breast cancer.
• •2. Previous treatment with cdk4/6 inhibitors.
• •3. Major surgery, chemotherapy, radiotherapy, any research drug or other anti-cancer treatment within 2 weeks before entering the trial.
• •4. Any other malignant tumor diagnosed within 3 years before entering the study, except non-melanoma skin cancer, basal cell or squamous cell skin cancer or cervical carcinoma in situ after radical treatment.
• •5. Human immunodeficiency virus (HIV) infection or known acquired immunodeficiency syndrome (AIDS), active hepatitis B (HBV DNA ≥ 1000 IU/ml), hepatitis C (HCV antibody positive and HCV-RNA higher than the detection limit of the analytical method) or combined hepatitis B and hepatitis C co-infection.
• •6. Within 6 months before entering the study, the following conditions occurred: myocardial infarction, severe / unstable angina pectoris, NYHA grade 2 or above cardiac insufficiency, persistent arrhythmia ≥ grade 2 (according to nci-ctcae version 5.0), atrial fibrillation at any level, coronary / peripheral artery bypass grafting, symptomatic congestive heart failure, cerebrovascular accident (including transient ischemic attack or symptomatic pulmonary embolism).
• •7. Inability to swallow, intestinal obstruction or other factors affecting drug administration and absorption.