What is the role of biosimilar G-CSF agents in hematopoietic stem cell mobilization at present?

Mobilization of hematopoietic stem cells, which has largely replaced bone marrow harvesting as a source of hematopoietic stem cells, using recombinant agents such as filgrastim or lenograstim has become a standard procedure in both patients and healthy donors prior to peripheral blood stem cell collection for autologous and allogeneic stem cell transplantation. Published literature data suggest that mobilization with recombinant granulocyte-colony stimulating factor (G-CSF) is safe and mobilization outcomes are satisfactory. In recent years, besides G-CSF originators, biosimilar G-CSF agents have been approved by the regulatory agencies for the same indications. Current data showed that by using the biosimilar G-CSF, similar results regarding safety and efficacy of hematopoietic stem cell mobilization may be achieved compared to the originator G-CSF. Although the issues such as the similarity to a licenced biological medicine, differences in manufacturing processes, the potential to cause immunogenicity, extrapolation and interchangeability of these biosimilar products are still being discussed by the scientific area, however, more experience with these agents now exists in approved endications and there seems to be no reason to expect significant differences between biosimilar G-CSF and originator G-CSF regarding their efficacy and safety in both patients and healthy donors. Also, the significant cost savings of biosimilars in real life setting may enhance the use of these agents in the future. Nonetheless, the collection of long-term follow-up data is mandatory for both patients and healthy donors, and multicentre randomized clinical trials that directly compare biosimilar G-CSF with the originator G-CSF are needed in order to allow the transplant community to make informed decisions regarding the choice of G-CSF.