Open-Label, Phase 1 Study to Evaluate Duration of Severe Neutropenia After Same-Day Dosing of Eflapegrastim in Patients With Breast-Cancer

Inclusion Criteria:

Willing and capable of giving written Informed Consent and able to adhere to study drug dosing time and blood draw schedules
New diagnosis of histologically confirmed early-stage breast cancer (ESBC), defined as operable Stage I to Stage IIIA breast cancer
Candidate to receive adjuvant or neoadjuvant TC chemotherapy
Age must be at least 18 years for the Early Phase, and between 18 to ≤55 years for the Expansion Phase
ANC ≥1.5×10^9/liter (L).
Platelet count ≥100×10^9/liter (L).
Hemoglobin >10 grams per deciliter (g/dL).
Calculated creatinine clearance >50 milliliter per minute (mL/min).
Total bilirubin ≤1.5 milligrams per deciliter (mg/dL).
Aspartate aminotransferase (AST)/serum glutamic oxaloacetic transaminase (SGOT) and alanine aminotransferase (ALT)/serum glutamic pyruvic transaminase (SGPT) ≤2.5×upper limit of normal (ULN).
Alkaline phosphatase ≤2.0×ULN.
Eastern Cooperative Oncology Group (ECOG) ≤2
Willing to practice 2 forms of contraceptives (1 must be a barrier method), from study entry through 30 days after last dose of study drug/ early discontinuation
Negative urine pregnancy test within 30 days before randomization

Exclusion Criteria:

Active concurrent malignancy (except non melanoma skin cancer or carcinoma in situ of the cervix) or life-threatening disease
Known sensitivity to Escherichia coli (E. coli) derived products
Concurrent adjuvant cancer therapy other than the trial-specified therapies
Locally recurrent/metastatic breast cancer
Previous exposure to filgrastim, pegfilgrastim, or other G-CSF products in clinical development within 3 months prior to the administration of study drug
Receiving anti-infectives, has an underlying medical condition or other serious illness that would impair the ability to receive protocol-specified treatment
Used any investigational drugs, biologics, or devices within 30 days prior to study treatment or plans to use any of these during the course of the study
Prior bone marrow or stem cell transplant
Prior radiation therapy within 30 days prior to enrollment
Major surgery within 30 days prior to enrollment
Pregnant or breastfeeding