Safety and efficacy of pegfilgrastim in patients receiving myelosuppressive chemotherapy

The major dose-limiting toxicity associated with myelosuppressive chemotherapy is neutropenia, which can be ameliorated with proactive administration of granulocyte colony-stimulating factor (G-CSF). Pegfilgrastim is a long-acting G-CSF, recently approved by the Food and Drug Administration. The efficacy and safety of pegfilgrastim administered once/chemotherapy cycle have been evaluated in clinical trials involving patients treated with myelosuppressive chemotherapy for breast cancer, lung cancer, non-Hodgkin's lymphoma, and Hodgkin's disease. Two pivotal phase III trials in patients with breast cancer showed that pegfilgrastim is as effective as filgrastim regarding the primary efficacy end point, which was duration of grade 4 (severe) neutropenia in cycle I of myelosuppressive chemotherapy. Secondary end points were the frequency of fever with neutropenia (febrile neutropenia), duration of neutropenia in cycles 2-4, depth of the absolute neutrophil count (ANC) nadir, and time to ANC recovery in cycles 1-4. Once/cycle pegfilgrastim 100 mug/kg or 6 mg was as safe and effective as daily filgrastim 5 mug/kg in reducing the frequency and duration of severe neutropenia. A trend toward a greater reduction in the overall frequency of febrile neutropenia with pegfilgrastim was observed. The availability of pegfilgrastim simplifies the use of prophylactic G-CSF, with the potential to increase patient convenience and adherence in management of chemotherapy-induced neutropenia.