In a randomized, open-label study, we discovered that tbo-filgrastim (Granix) can be used in the place of filgrastim (Neupogen) for autologous stem cell mobilization for multiple myeloma and non-Hodgkin’s lymphoma with no significant differences in efficacy or toxicity.
Autologous hematopoietic stem cell transplantation (Auto-HSCT) has shown to improve survival in multiple myeloma (MM) and relapsed Non-Hodgkin Lymphoma (NHL) and continues to be a potential option for various other hematologic malignancies and some solid tumors.
Filgrastim has been extensively used either alone or in combination with plerixafor (a CXCR4 antagonist) for stem cell mobilization across Europe and the United States. Tbo-filgrastim is a biosimilar approved in Europe for stem cell mobilization. However, tbo-filgrastim is currently listed as a new biologic in USA and as such, doesn’t carry the indication for stem cell mobilization in United states.
We conducted the first US prospective randomized open-label phase-II non-inferiority trial comparing tbo-filgrastim to Filgrastim for autologous stem cell mobilization in patients with MM/NHL undergoing auto-HSCT. Patients with MM/NHL were randomized 1:1 to tbo-filgrastim or filgrastim (10μg/kg) given subcutaneously 4 days followed by one dose of plerixafor (0.24 mg/kg) on day 4. Apheresis procedure was performed starting day 5 for up to 3 days to collect at least 5.0 x 106 CD34+ cells/kg.
Among the 97 patients we evaluated, 49 were randomized to tbo-filgrastim arm and 51 patients to the filgrastim arm. Patient characteristics were well matched between the groups, with the exception of age being relatively younger in the filgrastim cohort. Tbo-filgrastim was non-inferior to filgrastim in day 5 CD 34+ cell collection (11.6 CD34+ cells/kg ±6.7 versus 10.0 CD34+ cells/kg ± 6.8). A total of 83% patients in tbo-filgrastim arm and 76% in filgrastim arm collected the target number of CD34+ cells in one apheresis procedure.
Multivariate analysis we conducted showed a trend towards increased total stem cell yield in tbo-filgrastim arm, although it proved not to be statistically significant. Similarly, we observed a pattern of increased mobilization in the tbo-filgrastim arm, but this too was not statistically significant.
Only 4% in either arm had mobilization failures (unable to collect 5.0 x 106 CD34+ cells/kg after 3 apheresis procedures).
No difference in rate of adverse events were noted between the arms. Most commonly reported AEs were bone pain (42%), thrombocytopenia (39%), anemia (32%), alkaline phosphatase increased (23%), and nausea and or vomiting (21%).
We concluded that tbo-filgrastim can be substituted for filgrastim for autologous stem cell mobilization in MM/NHL patients. Our research further shows that tbo-filgrastim is a cost-effective alternative (due to low acquisition costs) to filgrastim for autologous stem cell mobilization.
Pavan Bhamidipati MBBS, MD, Washington University School of Medicine (St Louis, MO), was the lead author of this study: “Results of Prospective Randomized, Open Label, Non -Inferiority Study of Tbo-Filgrastim (Granix®) Versus Filgrastim (Neupogen®) in Combination with Plerixafor for Autologous Stem Cell Mobilization in Patients with Multiple Myeloma or Non -Hodgkin Lymphoma.” The study was published online (August 7, 2017) in the journal Biology of Blood and Marrow Transplantation (doi:10.1016/j.bbmt.2017.07.023).