Inclusion Criteria:
1. Able and willing to provide written, dated informed consent prior to any study specific procedures.
2. Able to comply with study procedures and visits for the entire study duration.
3. Male or female, 18 to 55 years of age at the time of signing the informed consent.
4. BMI between 18.0 and 30.0 kg/m².
5. Body weight 50-110 kg.
6. Healthy as determined by medical history, physical examination, vital signs, 12-lead ECG, laboratory assessments (biochemistry, hematology, urinalysis), and other screening evaluations, as applicable, with results within reference ranges or judged not clinically significant by the Investigator.
7. Hematology parameters, including absolute neutrophil count (ANC), hemoglobin, platelet count, and total white blood cell (WBC) count, within the laboratory reference ranges or considered clinically acceptable by the Investigator at screening.
8. Female participants of childbearing potential must use highly effective contraception (e.g., intrauterine device, hormonal implant, or a combined hormonal contraceptive) starting at least 4 weeks before first dosing and continuing until 4 weeks after the last study drug administration.
9. Female participants of non childbearing potential must be either post menopausal (≥12 consecutive months of amenorrhea) or surgically sterile.
Exclusion Criteria:
1. Pregnant or breastfeeding females.
2. Known hypersensitivity to filgrastim, other G-CSF products, Escherichia coli-derived proteins, or any excipient of the study drugs.
3. Known latex allergy.
4. Known history or suspected Hereditary Fructose Intolerance (HFI).
5. Known history, diagnosis, or screening evidence of clinically significant Sickle Cell Disorder.
6. Any clinically significant history or presence of cardiovascular, renal, pulmonary, neurological, musculoskeletal, hepatic, gastrointestinal, endocrinological, metabolic or psychiatric disease.
7. Any clinically significant history or presence of hematologic disease (e.g., leukemia, myelodysplastic syndrome, aplastic anemia, chronic neutropenia, thrombocytopenia, coagulopathy).
8. History or presence of clinically significant splenomegaly, splenic rupture, or splenectomy at screening.
9. History or presence of clinically significant respiratory or pulmonary disease (such as moderate-to-severe asthma, COPD, interstitial lung disease, pulmonary hypertension, acute respiratory distress syndrome \[ARDS\], or pulmonary hemorrhage) at screening.
10. History or presence of clinically significant systemic autoimmune or chronic inflammatory disease (such as systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, vasculitis, or autoimmune thyroid disease requiring systemic therapy).
11. History of alcohol abuse within 12 months prior to screening.
12. Smokers who consume more than 10 cigarettes per day (or equivalent nicotine products).
13. Receipt of any live or live-attenuated vaccine (e.g., MMR, varicella, yellow fever, oral typhoid) within 28 days prior to first study drug administration, or any inactivated, subunit, mRNA, or non-live vaccine (e.g., seasonal influenza, hepatitis A/B, tetanus, COVID-19) within 14 days prior to the first study drug administration.
14. Positive test results for drugs of abuse screening in urine at screening or before each treatment period.
15. Positive test results at screening for hepatitis B surface antigen (HBsAg, serum), or combined HIV antigen/antibody (HIV Ag-Ab, serum). Participants with a positive hepatitis C virus antibody (HCV Ab, serum) result will undergo confirmatory PCR testing and may be eligible if the PCR result is negative.
16. Positive pregnancy test for females of childbearing potential at screening or before each treatment period.
17. Whole blood donation more than 400 mL or significant acute blood loss within 8 weeks prior to screening.
18. Plasma, platelet, or apheresis donation within 4 weeks prior to screening.
19. Prior use of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), or other hematopoietic growth factors within 3 months prior to the first study drug administration.
20. Prior use of erythropoiesis-stimulating agents within 3 months prior to the first study drug administration.
21. Use of systemic corticosteroids or other immunosuppressants within 30 days prior to the first study drug administration.
22. Prior use of biological immunomodulators (such as tumor necrosis factor \[TNF\] inhibitors) within 3 months or 5 elimination half-lives (whichever is longer) prior to the first study drug administration.
23. Prior use of cytotoxic or antimetabolite agents within 30 days prior to the first study drug administration.
24. Participation in another interventional clinical trial involving administration of an investigational medicinal product, or receipt of an investigational medicinal product, within 90 days or 5 elimination half-lives (whichever is longer) prior to the first study drug administration
25. Use of any other prescription or OTC medication, herbal product, vitamin, or dietary supplement that, in the Investigator's judgment, may affect hematopoiesis, immune function, filgrastim pharmacokinetics/pharmacodynamics, or study safety assessments within 14 days or 5 elimination half-lives (whichever is longer) prior to the first study drug administration.
26. Any psychiatric, cognitive, or other condition that, in the investigator's opinion, could compromise the participant's ability to give truly informed consent, comply with study procedures, or safely complete the study.
27. Any other condition or circumstance that, in the Investigator's medical judgment, renders the participant unsuitable for participation in the study.
