[Efficacy and safety of biosimilar filgrastim for autologous peripheral blood stem cell harvest and transplantation: a single-institutional retrospective analysis].

Three biosimilar filgrastim products are currently available in Japan. Among these, the safety and efficacy of two imported drugs for autologous peripheral blood stem cell harvest (autoPBSCH) and autologous peripheral blood stem cell transplantation (autoPBSCT) have been studied widely; however, evidence of the safety and efficacy of domestically manufactured filgrastim is limited. Therefore, we compared the efficacy and safety of domestic biosimilar filgrastim (BF1, n=23) with those of originator filgrastim (OF, n=21) for autoPBSCH and autoPBSCT. Before autoPBSCH, the same median total dose of 3.3 mg filgrastim was administered to patients in the BF1 and OF groups. Median numbers of CD34-positive cells harvested did not significantly differ between BF1 (4.32×106 /kg) and OF (4.75×106 /kg) groups. After autoPBSCT, the median total doses of BF1 and OF used for neutrophil recovery were 2.7 and 3.3 mg, respectively. There were no significant inter-group differences in the time to bone marrow recovery, total transfusion units, hospitalization duration, overall survival at 1 year, or adverse events. Compared with OF, the cost of BF1 was considerably lower by 229,529 yen per transplantation case. Thus, the efficacy and safety of BF1 were comparable to those of OF, making BF1 an effective and economical alternative to OF.