G-CSF biosimilars vs. originator filgrastim for febrile neutropenia prophylaxis: systematic review of cost-effectiveness, safety, and clinical outcomes

Background: Granulocyte-colony-stimulating factors (G-CSFs) help avoid the serious complication of febrile neutropenia (FN) among cancer patients being treated with chemotherapy. Since biosimilar G-CSFs have joined the market, it is necessary to compare them to traditional G-CSFs in terms of safety, effectiveness, and costs for proper medical care. Methods: According to PRISMA, a qualitative systematic review was completed using studies up to February 2025. Only randomized controlled trials and observational studies on biosimilar G-CSFs against originator products were added to the selection. The primary outcomes measured were the incidence of FN, duration of severe neutropenia (DSN), time to absolute neutrophil count recovery, adverse effects, and the cost–benefits of treatment. Results: In 31 studies with 15 728 patients, biosimilar G-CSFs proved as effective as reference products in reducing FN and DSN. FN rates were 12.1–15.8% with biosimilars versus 12.5–16.1% with reference filgrastim. DSN was noninferior (mean difference 0.1 days; 95% CI: −0.2, 0.4). Safety profiles were similar, with treatment-emergent adverse events in 71.1–84.7% of biosimilar patients and 68.9–82.5% of reference patients. Importantly, biosimilars cost 15–32% less, supporting their use as effective, safe, and more affordable alternatives. Conclusion: Biosimilar G-CSFs are as effective and safe as reference products for protection against FN and offer much lower pricing (15–32% savings). The results support the broader use of biosimilar G-CSFs in the clinic, which may help more patients gain access to these critical medications.