Pegfilgrastim use during chemotherapy: current and future applications

Chemotherapy-induced myelosuppression is the most common dose-limiting side effect of cancer chemotherapy. Neutropenia is a serious risk with chemotherapy, associated with infectious complications, use of intravenous antibiotics, hospitalization, and even death. The occurrence of febrile neutropenia can lead to dose reductions and delay in subsequent cycles of chemotherapy that may have a detrimental affect on overall survival and disease-free survival. Granulocyte colony-stimulating factors (G-CSF) can reduce the duration of severe neutropenia, the incidence of febrile neutropenia, and allow planned dosing and timing of chemotherapy. Filgrastim is a G-CSF that has demonstrated benefit for the treatment and prophylaxis of chemotherapy-induced neutropenia (CIN), but its short half-life requires repeated daily subcutaneous injection. Pegfilgrastim is a recombinant G-CSF created by attaching a polyethylene glycol (PEG) molecule to the filgrastim protein. Once-per-cycle dosing of pegfilgrastim has been evaluated in clinical trials using myelosuppressive chemotherapy in breast cancer, Hodgkin's lymphoma, and non-Hodgkin's lymphoma. Trials have demonstrated that pegfilgrastim is comparable in safety and efficacy to filgrastim for decreasing the duration of severe neutropenia after chemotherapy in patients with nonmyeloid malignancy. This review will summarize recent clinical trial results and novel uses of pegfilgrastim.