A Systematic Literature Review of the Efficacy, Effectiveness, and Safety of Filgrastim

Purpose: Filgrastim (NEUPOGEN) is the originator recombinant human granulocyte colony-stimulating factor widely used for preventing neutropenia-related infections and mobilizing hematopoietic stem cells. This report presents findings of a systematic literature review and meta-analysis of efficacy and safety of originator filgrastim to update previous reports.

Methods: A literature search of electronic databases, congress abstracts, and bibliographies of recent reviews was conducted to identify English-language reports of clinical trials and observational studies evaluating filgrastim in its US-approved indications up to February 2015. Two independent reviewers assessed titles/abstracts and full texts of publications, and extracted data from studies that compared originator filgrastim vs placebo or no treatment. For outcomes with sufficient homogeneous data reported across studies, meta-analysis was performed and relative risk (RR) determined. Data were summarized descriptively for all other evaluated outcomes.

Results: A total of 1194 unique articles evaluating originator filgrastim were identified, with 25 meeting eligibility criteria for data extraction: 18 randomized controlled trials, 2 nonrandomized clinical trials, and 5 observational studies. In chemotherapy-induced neutropenia (CIN), filgrastim vs placebo or no treatment significantly reduced febrile neutropenia incidence (RR 0.63, 95% CI 0.53-0.75) and grade 3 or 4 neutropenia incidence (RR 0.50, 95% CI 0.37-0.68). The most commonly reported adverse event (AE) with filgrastim was bone pain (RR 2.61, 95% CI 1.29-5.27 in CIN). Additional efficacy and safety outcomes are described within indications.

Conclusions: This systematic literature review and meta-analysis confirms and updates previous reports on the efficacy and safety of originator filgrastim. Bone pain was the commonly reported AE associated with filgrastim use.