Methods of treating neutorpenia using G-CSF protein complex

1. A method of increasing stem cell production in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a chemotherapeutic regimen followed by a therapeutically effective amount of a protein complex comprising a modified human granulocyte-colony stimulating factor (hG-CSF) covalently linked to an immunoglobulin Fc region via a non-peptidyl polymer, wherein the non-peptidyl polymer is site-specifically linked to an N-terminus of the immunoglobulin Fc region and the modified hG-CSF comprises the amino acid sequence of SEQ ID NO: 1.

2. The method of claim 1 , wherein the protein complex is administered on the same day as a chemotherapeutic regimen.

3. The method of claim 2 , wherein the protein complex is administered to the patient within 30 minutes, 2 hours, 3 hours, 5 hours, 8 hours, or 12 hours of completion of the chemotherapeutic regimen.

4. The method of claim 1 , wherein the protein complex is administered between 1 and 5 days after the subject is treated with adjuvant or neoadjuvant chemotherapy.

5. The method of claim 4 , wherein the adjuvant or neoadjuvant chemotherapy is a combination of docetaxel and cyclophosphamide.

6. The method of claim 1 , wherein the subject has breast cancer.

7. The method of claim 1 , wherein a second dose of the protein complex is administered between 15 and 25 days after a first dose of the protein complex is administered to the subject.

8. The method of claim 1 , wherein the therapeutically effective amount is a unit dosage between about 5 μg/kg and about 200 μg/kg.

9. The method of claim 1 , wherein the therapeutically effective amount is 13.2 mg of the protein complex in a 0.6 mL dosage volume.

10. The method of claim 1 , wherein the immunoglobulin Fc region comprises a polypeptide sequence of SEQ ID NO: 2.

11. The method of claim 1 , wherein:

(a) the immunoglobulin Fc region is aglycosylated;

(b) the immunoglobulin Fc region consists of one to four domains selected from the group consisting of CHI, CH2, CH3, and CH4 domains;

(c) the immunoglobulin Fc region further comprises a hinge region; or

(d) the immunoglobulin Fc region is an immunoglobulin Fc fragment derived from IgG, IgA, IgD, IgE, or IgM.

12. The method of claim 1 , wherein:

(a) each domain of the immunoglobulin Fc fragment is a hybrid of domains, in which each domain has a different origin derived from immunoglobulins selected from the group consisting of IgG, IgA, IgD, IgE, and IgM;

(b) the immunoglobulin Fc fragment is a dimer or multimer consisting of single chain immunoglobulins comprising domains having the same origin;

(c) the immunoglobulin Fc fragment is an IgG4 Fc fragment; or

(d) the immunoglobulin Fc fragment is a human aglycosylated IgG4 Fc fragment.

13. The method of claim 1 , wherein the non-peptidyl polymer is selected from the group consisting of polyethylene glycol, polypropylene glycol, an ethylene glycol-propylene glycol copolymer, polyoxyethylated polyol, polyvinyl alcohol, polysaccharide, dextran, polyvinyl ethyl ether, a biodegradable polymer, a lipid polymer, chitin, hyaluronic acid, and a combination thereof.

14. The method of claim 1 , wherein the non-peptidyl polymer is polyethylene glycol.

15. The method of claim 14 , wherein the polyethylene glycol has a molecular weight of 3.4 kDa.