Study of the Efficacy and Safety of Empegfilgrastim for Neutropenia Prophylaxis in Breast Cancer Patients

Inclusion Criteria:

* Signed informed consent form;
* Histologically verified diagnosis of stage IIb/III/IV breast cancer;
* Age of 18-70 years inclusive;
* Life expectancy of at least 6 months after inclusion in the study;
* If the patient had received the chemotherapy for breast cancer, it should be finished 30 days before the beginning of the study;
* ECOG Performance Status of 0- 2, not increasing within during 2 weeks before randomization;
* ANC level of 1500/μL and more at the beginning of the study
* Platelet count of 100 000/μL and more at the beginning of the study
* Hemoglobin level of 90 g/l and more
* Creatinine level \<1.5 mg/dl
* Total bilirubin level \<1.5 × the upper limit of normal (ULN)
* ALT and/or AST levels \<2.5×ULN (5×ULN for patients with liver metastases);
* Alkaline phosphatase \<5×ULN;
* Left ventricular ejection fraction \>50% and more;
* If the patient had received adjuvant and/or neoadjuvant therapy, the cumulative dose of anthracyclines should not exceed 250 mg/m2 for doxorubicin or 540 mg/m2 for epirubicin,if in this study planned 6 cycles of chemotherapy ;
* If the patient had received adjuvant and/or neoadjuvant therapy, the cumulative dose of anthracyclines should not exceed 350 mg/m2 for doxorubicin or 660 mg/m2 for epirubicin,if in this study planned 4 cycles of chemotherapy ;
* Ability of the participant to follow the protocol requirements, according to the Investigator's opinion;
* Patients of childbearing potential must implement reliable contraceptive measures during the study treatment, starting 4 weeks prior randomization and for 6 months after the last administration of the study drug;
* Patients should be able to follow the Protocol procedures (according to Investigator's assessment.

Exclusion Criteria:

* Patient has received two or more chemotherapy regimens for the metastatic breast cancer;
* Documented hypersensitivity to filgrastim, pegfilgrastim, docetaxel, doxorubicin, dexamethasone and/or its excipients, PEGylated drugs, recombinant proteins.
* Pregnancy or breastfeeding;
* Systemic antibiotic therapy within 72 h prior empegfilgrastim/filgrastim administration;
* Concomitant radiotherapy (except selective radiotherapy of bone metastases);
* Surgery, radiotherapy (except selective radiotherapy of bone metastases), administration of any experimental drugs within 30 days prior randomization;
* History of bone marrow/stem cell transplantation;
* Conditions limiting the patient's ability to follow the protocol;
* CTCAE grade 3-4 neuropathy;
* HIV, HCV, HBV, T.Pallidum infection(s);
* Acute or active chronic infections;
* Severe concurrent diseases (for example, severe arterial hypertension, severe heart failure, and other);
* Severe depression, schizophrenia, any other mental disorders;
* Obstacles in intravenous administration of study drugs;
* Simultaneous participation in other clinical trials, previous participation in other clinical trials within 30 days before entering into the trial, previous participation in the same trial.