A single-center, retrospective analysis to compare the efficacy and safety of filgrastim-sndz to filgrastim for prophylaxis of chemotherapy-induced neutropenia and for neutrophil recovery following autologous stem cell transplantation

Filgrastim-sndz (Zarxio®) was approved by the FDA in March 2015 as a biosimilar product of its reference product, filgrastim (Neupogen®) for all five indications. The NCCN Clinical Practice Guidelines has incorporated filgrastim-sndz into its recommendations as a category 1 recommendation for use in settings of febrile neutropenia, myelosuppressive chemotherapy administration, and post-hematopoietic stem cell transplant (HSCT). As a cost-saving initiative, our institution switched from filgrastim to filgrastim-sndz for all indications starting in March 2016. The purpose of this study was to assess for any difference in clinical or safety outcomes between filgrastim and filgrastim-sndz. This is an IRB-approved, single institution, 1-year retrospective chart review (September 2015 to August 2016) conducted in hospitalized adults who received either filgrastim or filgrastim-sndz either for prophylaxis of chemotherapy-induced myelosuppression or for neutrophil recovery after autologous HSCT. Our data showed no differences in duration of G-CSF therapy (7.96 vs. 8.5 days, P = 0.36), white blood count (WBC) (8.99 vs. 8.04, P = 0.28), absolute neutrophil count (ANC) (7.62 vs. 6.91 × 10⁹/L, P = 0.36) at the time of granulocyte-colony stimulating factor (G-CSF) discontinuation, or safety of filgrastim and filgrastim-sndz. The efficacy and safety of filgrastim and filgrastim-sndz were similar for prophylaxis of chemotherapy-induced neutropenia and neutrophil recovery post-autologous HSCT.