Efficacy of three filgrastim-intended copies for hematopoietic stem cell mobilization in healthy adult and pediatric donors in Mexico.

INTRODUCTION: The use of filgrastim biosimilars for healthy adult and pediatric donor mobilization in hematopoietic stem cell transplantation has been met with increased safety and efficacy concerns in contrast to generic small molecule drugs. In Mexico, several filgrastim-intended copies (FIC) have been available and marketed since 2001, while no clinical comparability studies to evaluate their use in this setting have been published and thus are not considered to be true biosimilars. In this study, we report our experience using three different FIC products currently available (Filatil, Dextrifyl, and Biofilgran). METHODS: We retrospectively evaluated 118 related donors of all ages who received any brand 5 µg/kg subcutaneously twice daily for 4 days and were harvested in a single apheresis system on day 5. RESULTS: Donors had a median age of 38 years (range, 1-69). A successful harvest defined as ≥2 × 106 CD34+ cells/kg of recipient weight was achieved in 95.8% of cases, with a median CD34+ cell dose of 9.4 × 106 /kg (range 1-42.8). A single apheresis session was performed in 89.8% of cases. No significant difference in cell yield between each brand was observed. All pediatric donors had a successful harvest with similar results to adult donors. No immediate severe adverse effects were documented in any case. CONCLUSIONS: In conclusion, three FICs available in Mexico were efficacious and without immediate severe adverse effects, resulting in significant cost savings. Evaluation of immunogenicity and establishment of a pharmacovigilance program with the use of FICs is warranted.