Effectiveness and Safety of Filgrastim (Neupogen™) versus Filgrastim-aafi (Nivestim™) in Primary Prophylaxis of Chemotherapy-Induced Febrile Neutropenia: An Observational Cohort Study

Abstract

Background: Despite the demonstrated efficacy and safety of biosimilar filgrastim-aafi (Nivestim™), few studies have compared its use in real-life clinical practice to the originator filgrastim (Neupogen™). Objectives: This study aimed to compare the effectiveness and safety of filgrastim and filgrastim-aafi for the primary prophylaxis of chemotherapy induced-febrile neutropenia in the real-life setting. Patients and methods: A retrospective cohort study included all adult cancer patients at the King Hussein Cancer Centre requiring primary prophylaxis for chemotherapy-induced febrile neutropenia between 2014 and 2016. Two cohorts were selected: patients who received filgrastim and those who received filgrastim-aafi. The primary endpoint was the incidence of febrile neutropenia; the secondary endpoints were the incidence of adverse drug reactions (ADRs), hospital admissions due to febrile neutropenia, and the mean length of hospitalization. Chi-squared tests were performed to evaluate differences between groups. Logistic regression was conducted to adjust for confounding factors. Results: A total of 268 patients were identified, with 88 in the filgrastim cohort and 180 in the filgrastim-aafi cohort; 64%were females. The mean age was 47 (±15) years. The incidence of febrile neutropenia was 21.6% in the filgrastim cohort and 15% in the filgrastim-aafi cohort (P = 0.179). No statistically significant differences were detected in the incidence of hospital admission (P = 0.551) or ADRs (P = 0.623) between the two cohorts. Upon adjusting for the confounding factors, results remained statistically insignificant. Conclusion: Filgrastim and filgrastim-aafi had comparable effectiveness and safety as primary prophylaxis for chemotherapy-induced febrile neutropenia. More extensive prospective studies with additional insight on the cost implications are required.