A long-acting, engineered and pegylated version of human granulocyte-colony stimulating factor (G-CSF), with potential hematopoietic activity. Similar to G-CSF, pegfilgrastim anti-neutropenic factor (ANF) binds to and activates specific cell surface receptors, and stimulates neutrophil progenitor proliferation and differentiation. Therefore, this agent may prevent the duration and incidence of chemotherapy-induced neutropenia. Compared to filgrastim, the conjugation with a branched polyethylene glycol molecule reduces renal clearance and increases its plasma half-life.