Comparison of Biosimilar Filgrastim with Innovator Fligrastim 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

Background: In the Middle East, there is lack of data on peripheral blood CD34+stem cells mobilization by using biosimilar filgrastim. We have been using both Neupogen and a biosimilar G-CSF) Zarzio (R) (as a mobilizing agent since February 2014 for both allogenic and autologous stem cell transplantations. Material/Methods: This was a single-center retrospective study. All patients and healthy donors who received either the biosim-ilar G-CSF (Zarzio (R)) or original G-CSF (Neupogen (R)) for mobilization of CD34+ stem cells were included in the study. The primary goal was to determine and compare the rate of successful harvest and amount of CD34+ stem cells collected in either adult cancer patients or healthy donors between Zarzio (R) and Neupogen (R) groups. Results: A total of 114 patients, including 97 cancer patients and 17 healthy donors, underwent successful CD34+ stem cell mobilization using G-CSF with chemotherapy (35 with Zarzio (R) +chemotherapy, 39 with Neupogen (R) +che-motherapy) or G-CSF as monotherapy (14 with Zarzio (R), 9 with Neupogen (R)) in autologous transplantation. In an allogeneic stem cell transplantation, successful harvest was achieved by using G-CSF monotherapy (8 with Zarzio (R), 9 with Neupogen (R)). There was no difference between Zarzio (R) and Neupogen (R) in the amount of CD34+ stem cells collected at leukapheresis. There was no difference with regards to secondary outcomes between the 2 groups. Conclusions: Our study showed that biosimilar G-CSF (Zarzio (R)) has comparable efficacy to the original G-CSF (Neupogen (R)) when used for mobilization in both autologous and allogenic stem cell transplantation and was associated with significant cost saving.