Novel methods of treating neutorpenia using g-csf protein complex

A method for increasing stem cell production in a subject, 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 substitutions in at least one of Cys17 and Pro65, wherein the protein complex is administered on the same day as the chemotherapeutic regimen.

The method of claim 23, 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.