Study of F-627 in Women With Breast Cancer Receiving Myelotoxic Chemotherapy

Inclusion Criteria:

1. 18-75 years old.
2. Female postoperative breast cancer patients who require adjuvant chemotherapy, and are planned to receive 4 cycles of EC chemotherapy;
3. East Cooperative Oncology Group (ECOG) performance 0-1.
4. Absolute neutrophil count (ANC) ≥ 2.0 × 10\^9/L, hemoglobin (Hb) ≥ 11.0 g/dl, and platelets (PLT) ≥ 100 × 10\^9/L prior to chemotherapy.
5. Hepatic and renal function within the normal range;.
6. Left ventricular ejection fraction (LVEF) \> 50%.
7. Willing to sign the informed consent form and able to comply with protocol requirements

Exclusion Criteria:

1. Women in pregnancy or breastfeeding; Women of child-bearing potential have a positive pregnancy test result prior to the first dose;
2. Life expectancy less than 12 months;
3. Radiation therapy within 4 weeks prior to enrollment;
4. Breast cancer patients who have received neoadjuvant chemotherapy before radical mastectomy;
5. Prior bone marrow or stem cell transplant;
6. With other malignant tumors other than breast cancer;
7. Have received granulocyte colony stimulating factor (G-CSF) treatment within 6 weeks prior to enrollment;
8. Diagnosed with acute congestive heart failure, cardiomyopathy, or myocardial infarction by clinical diagnosis, electrocardiograph (ECG) or other approaches;
9. With any disease that may cause splenomegaly;
10. With acute infection, chronic active Hepatitis B within 1 year (unless patients tested negative for HBsAg prior to enrollment), or Hepatitis C;
11. History of tuberculosis (TB); history of TB exposure, unless negative for tuberculin test; TB patients undergoing treatment; or suspected TB evaluated by chest x-ray;
12. Known human immunodeficiency virus (HIV) positive or acquired immune deficiency syndrome (AIDS);
13. With sickle cell anemia;
14. With alcohol or drug abuse that may affect the compliance with the study;
15. With known hypersensitivity to E. coli derived proteins, G-CSF, or excipients;
16. Has received any other investigational drug within 4 weeks prior to enrollment;
17. Patients with diseases or symptoms unsuitable for participating in the clinical trial based on the investigator's judgment;