Real world comparison of filgrastim to filgrastim-sndz in patients with chemotherapy-induced neutropenia.

Introduction: There exists some apprehension by prescribers, healthcare providers, and other stakeholders regarding the real-world safety and effectiveness of biosimilars. While some of the apprehension is likely due to clinician knowledge gaps in the biosimilarity exercise, additional data (including those generated from the real-world) regarding safety and efficacy could reduce a clinician's perception of biosimilar uncertainty and can potentially increase biosimilar acceptance and uptake. The published literature is lacking regarding the real-world impact on healthcare costs and clinical outcomes when a single healthcare institution converts from filgrastim to filgrastim-sndz as its short-acting Granulocyte Colony Stimulating Factor (GCSF), especially within diverse populations and indications not explicitly studied through the registration trials. Specifically, both filgrastim and filgrastim-sndz possess FDA-approved indications within patients with hematologic malignancies receiving high-dose chemotherapy and in those undergoing bone marrow transplantation. As a biosimilar to filgrastim, the FDA did not require prospective, randomized controlled trials to obtain these indications for filgrastim-sndz. The purpose of this study is to describe real-world healthcare resource costs, utilization patterns, and clinical outcomes in patients with hematologic malignancies who received filgrastim-sndz or filgrastim to support neutrophil recovery following chemotherapy (i.e., induction or consolidation) or a bone marrow transplant (BMT) at Yale New Haven Hospital (YNHH).

Methods: A total of 148 patients were identified and met the following criteria: at least 18 years old, Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2, absence of fever or infection, newly diagnosed acute myeloid leukemia or newly post-bone marrow transplant and received filgrastim-sndz (Zarxio^®) or reference filgrastim (Neupogen^®).

Results: Healthcare resource utilization outcomes were compared between biosimilar and reference filgrastim using descriptive statistics. There were no major differences between either cohort, including duration of hospitalization, the number of overall emergency room visits and additional hospital admissions with a primary diagnosis of febrile neutropenia or neutropenia within 30 days post-discharge from initial hospital admission, time to neutrophil recovery following GCSF support, and the incidence and duration of both fever and febrile neutropenia. The total cost based on treatment of all patients in each arm differed significantly with filgrastim-sndz being the most cost-effective choice.

Conclusion: filgrastim-sndz significantly reduced healthcare utilization costs compared to reference filgrastim with similar effect on absolute neutrophil count, incidence of fever, and febrile neutropenia.