Pegfilgrastim

Pegfilgrastim is a PEGylated form of the recombinant human granulocyte colony-stimulating factor (GCSF) analog, filgrastim. Like GCSF, the pegylated form serves to stimulate the level of white blood cells (neutrophils).

Amgen manufactures pegfilgrastim under the brand name Neulasta, and Roche under the name Neulastim. The drug is prepared by coupling a 20 kDa Polyethylene glycol (PEG) molecule to the N-terminus of the filgrastim protein. Pegfilgrastim has a human half-life of 15 to 80 hours, much longer than the parent filgrastim (3–4 hours).

Pegfilgrastim treatment can be used to stimulate the bone marrow to produce more neutrophils to fight infection in patients undergoing chemotherapy. Pegfilgrastim can be given on the first day of chemotherapy. As it supports white blood cell production, using this medicine prophylactically can allow an increased dose intensity of chemotherapy agents. Chemotherapy cycles can be repeated with greater frequency (increased dose-density), diminishing tumor regrowth.