Starting on the fourth day of each course, you will be given a daily injection of the drug Filgrastim. Filgrastim is a growth factor naturally produced in the body to stimulate the production of white blood cells (infection fighting cells). Filgrastim can now be produced in the laboratory and given to patients at higher doses than the body makes. Filgrastim should help the body recover from treatment. Filgrastim will be given as an injection under the skin once a day until an acceptable number of white blood cells are detected in the bloodstream.