Filgrastim Biosimilar Demonstrated Comparable Efficacy to Originator Filgrastim in Peripheral Blood CD34+ Stem Cell Mobilization Among Patients With Hematologic Malignancies

Results from a Single-Center Retrospective Study

A filgrastim biosimilar had similar efficacy in peripheral blood CD34+ stem cell mobilization for both autologous (autoSCT) and allogeneic stem cell transplantation (alloSCT) compared to originator filgrastim among patients with hematologic malignancies, according to findings from a retrospective study published in Annals of Transplantation. 

Maha M. Islami, MD, King Abdulaziz University, Jeddah, Saudi Arabia, and coauthors stated, “The original G-CSF (filgrastim) is widely used as a mobilizer of CD34+ stem cells among healthy donors in allogenic stem cell transplants or among cancer patients in autologous stem cell transplants as a standard of care. Alternatively, biosimilar filgrastim (G-CSF) can be used instead of originator filgrastim.” 

Although originator filgrastim is a widely used mobilizer, the biosimilar filgrastim could serve as a cost-effective alternative that may “reduce the time to neutrophil recovery and the duration of fever following induction or consolidation chemotherapy treatment,” as Dr Islami et al wrote. 

This study compared the efficacy of biosimilar and originator filgrastim. The primary endpoint was to achieve a “successful harvest,” defined as the collection of ≥2×106/kg CD34+ cells. The secondary endpoint was the time to achieve neutrophil and platelet engraftment. 

There were 114 patients who had previously received either originator or biosimilar filgrastim, made up of 97 patients with cancer and 17 healthy donors, enrolled in this trial and who underwent CD34+ stem cell mobilization. Of the patients with cancer, 45 had Hodgkin lymphoma, 29 multiple myeloma, and 14 other hematological leukemias. Of those patients, 35 received biosimilar filgrastim plus chemotherapy, 39 received originator filgrastim plus chemotherapy, and 14 received originator monotherapy in the context of alloSCT. Of the healthy donors, 8 received biosimilar filgrastim, and 9 received the originator. 

Results indicated that all patients underwent successful CD34+ stem cell mobilization. There was no difference between groups in the amount of CD34+ stem cells collected; the results remained consistent between drugs. Additionally, there was no difference in the median time to achieve neutrophil and platelet engraftment between groups. In terms of safety, there were no allergic reactions in either group, and the only adverse event (bone pain) was minimal and similar between groups. 

The study authors concluded that this “trial supports the use of biosimilar filgrastim in mobilization both in cancer patients and in healthy donors.” They added, “using biosimilar filgrastim reduces healthcare expenditure without affecting patient outcomes.”

Source: 

Islami MM, Mansoor Ahmed Khan, Aseeri MA, et al. Comparison of biosimilar filgrastim with innovator filgrastim for peripheral blood stem cells mobilization, collection of CD34+ stem cells, and engraftment in patients undergoing autologous and allogeneic stem cell transplantation: A single-center experience. Ann Transplant. Published online February 21, 2023. 2023;28. doi: 10.12659/aot.938585