Abstract P1-10-03: Biosimilar filgrastim in the treatment of patients with breast cancer undergoing neutropenia-inducing chemotherapy: A subanalysis of the NEXT study
Authors: Albrand H , Kamioner D , Leprêtre S 
Published: May 2016

Abstract
Introduction
Febrile neutropenia (FN) is a frequent and serious complication in breast cancer patients undergoing chemotherapy. In addition to being a major risk factor for infection-related morbidity/mortality and disease progression, FN can lead to dose delays and reduction. Nivestim™ (Hospira Inc), a biosimilar filgrastim, is a granulocyte colony-stimulating factor licensed for the treatment of neutropenia and FN induced by myelosuppressive chemotherapy.
The NEXT (Nivestim safety profile in patiEnts treated with cytotoXic CT in real-life clinical pracTice) study was a prospective real-world trial assessing the safety of curative or prophylactic biosimilar filgrastim in the treatment of patients undergoing chemotherapy. The large size of this study enabled a subanalysis to be performed in breast cancer patients; the results are presented herein.
Methods
NEXT was a prospective, noninterventional, longitudinal, multicenter French study (NCT01574235). Patients with a solid tumor or a malignant hemopathy (excepting chronic myeloproliferative and myelodysplastic syndromes) undergoing or starting neutropenia-inducing chemotherapy were enrolled. Objectives were to evaluate safety and incidence of FN and infection. Patients received biosimilar filgrastim (Hospira) and were monitored for 1–6 chemotherapy cycles, with 3 visits at inclusion, during, and following treatment.
Results
A total of 2114 patients were enrolled in this study; of these, 463 patients had breast cancer and were included in this analysis. Mean age was 58.4 years, 97% were female, 95.8% had an ECOG PS of 0–1, and 19.4% had metastatic disease. The majority of patients (n = 454; 98.1%) received biosimilar filgrastim as prophylaxis (primary, 94.1%; secondary, 5.9%); 9 (1.9%) patients received curative biosimilar filgrastim. Median time to initiation of biosimilar filgrastim was 7.5 days for curative patients and 4 days for prophylactic patients. Mean treatment duration was: 6.0±1.7 days (curative) and 5.6±2.6 days (prophylactic). Biosimilar filgrastim-related adverse events (AEs) were reported in 119 patients (curative, n = 1; primary prophylaxis, n = 111; secondary prophylaxis, n = 7). The rate of AEs was higher in breast cancer patients (26.1%) compared with the entire NEXT study population with solid tumors (21.1%); similar rates of FN were reported but breast cancer patients had higher rates of AEs and bone and muscle pain compared with the total study population. Considering the prophylactic group only, 4.7% experienced FN and 1.6% reported an infection. The incidence of FN and/or infection resulted in hospitalization in 4.7% of patients (mean duration: 4.6±2.5 days), chemotherapy dose reduction in 2.7% of patients, and a delay of chemotherapy in 5.2% of patients.
Conclusion
These data demonstrate the safety and efficacy of biosimilar filgrastim in a real-world setting. The subanalysis illustrated that biosimilar filgrastim was effective and well tolerated in breast cancer patients in the curative and prophylactic setting. These results mirror those of the parent NEXT study, and show that biosimilar filgrastim is a valid alternative therapeutic option for chemotherapy-induced neutropenia in breast cancer patients.
Citation Format: Albrand H, Kamioner D, Leprêtre S. Biosimilar filgrastim in the treatment of patients with breast cancer undergoing neutropenia-inducing chemotherapy: A subanalysis of the NEXT study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-10-03.