Home administration of filgrastim (Nivestim™) in primary prophylaxis of chemotherapy-induced febrile neutropenia

Burkhard Otremba,1 Carsten Hielscher,2 Volker Petersen,3 Christian Petrik4 1Oncological Practice Oldenburg/Delmenhorst, Oldenburg, Germany; 2Gynecology Competence Center Stralsund, Stralsund, Germany; 3Practice for Hematology and Oncology, Heidenheim, Germany; 4Pfizer Inc, Berlin, Germany Background: The granulocyte-colony stimulating factor (G-CSF) biosimilar filgrastim (Nivestim™) reduces the duration and severity of neutropenia and the frequency of occurrence of febrile neutropenia (FN). Administration of this biosimilar filgrastim and the patient population receiving it at home have not been sufficiently documented in day-to-day medical practice. Insight into home administration may help optimize the management of FN in this setting, potentially at a reduced cost and patient burden vs hospital administration. Materials and methods: This was a prospective, non-interventional, non-comparative, multisite study involving 171 patients across 29 sites treated with at least one dose of filgrastim. Mean age was 59.3 years, and most patients were female and G-CSF-naïve. The data collected originated from paper-based patient questionnaires and routine documentation by the treating physicians. The primary endpoint was the characterization of patients treated with filgrastim. Secondary endpoints were satisfaction with filgrastim, effectiveness, safety and tolerability, and compliance with prescription. Results: Most patients had solid tumors (95.9%), mainly located in the breast, while 4.7% had malignant hematological disease. Solid tumors were recorded as grade 1 (7.9%), grade 2 (28.0%), grade 3 (45.7%), and grade 4 (3.0%), and the majority of patients classified at TNM Stages I and II. Many patients (71.0%) could self-inject filgrastim and 72.2% found the handling instructions “extremely straightforward and easy to understand” at least once. Nearly all (99.4%) patients found the syringes “easy to use” at least once and 91.7% were willing to continue home administration. The mean patient satisfaction score for home administration was 1.9±0.9, ranging from 1 (very satisfied) to 6 (absolutely dissatisfied). No cases of neutropenia were observed and only one event of FN occurred. Conclusion: Home-based prophylaxis for FN with filgrastim was found to be effective, well tolerated, and well received by patients (ClinicalTrials.gov Identifier: NCT02956967). Keywords: neutropenia, filgrastim, biosimilar, oncology