Biosimilar filgrastim (Zarzio^®) vs. lenograstim (Myelostim^®) for peripheral blood stem cell mobilization in adult patients with lymphoma and myeloma: a single center experience

Lenograstim 5 µg/kg is not superior to biosimilar filgrastim 10 µg/kg in lymphoma patients undergoing peripheral blood stem cell mobilization after chemotherapy: preliminary results from a prospective randomized study

“…In the past years, several studies have been carried out with the aim to compare biosimilar and originator filgrastim in PBSC mobilization and autologous stem cell transplant, all confirming a substantial equivalence in terms of efficacy and safety. [7][8][9][10] However, there are only few retrospective studies comparing lenograstim with biosimilar filgrastim in hematologic patients undergoing PBSC mobilization, [11][12][13][14] while randomized trials focusing exclusively on lymphoma patients are lacking. Our recently published retrospective data suggested that only in lymphoma but not in myeloma patients lenograstim was more effective than biosimilar filgrastim when used at the same dosage of 5 mg/kg for PBSC mobilization, with a comparable safety profile.…”

“…Our recently published retrospective data suggested that only in lymphoma but not in myeloma patients lenograstim was more effective than biosimilar filgrastim when used at the same dosage of 5 mg/kg for PBSC mobilization, with a comparable safety profile. 12 Based on these considerations, we planned a prospective randomized study comparing, after chemotherapy, lenograstim at the conventional dosage of 5 mg/kg body weight with biosimilar filgrastim at the highest unconventional dosage of 10 mg/kg body weight with the aim to verify the hypothesis of lenograstim superiority in lymphoma patients undergoing PBSC mobilization even at half the dosage. Herein we report data from interim analysis carried out after enrolling 60% of planned patients.…”

“…However, randomized studies comparing lenograstim with biosimilar filgrastim are so far lacking; the only published comparisons are retrospective experiences which report an equivalence between the two G‐CSF formulations . From our previously published retrospective study, we suggested that lenograstim was more effective than biosimilar filgrastim at the same dosage in lymphoma but not in myeloma patients undergoing mobilization chemotherapy and PBSC collection . We hypothesized that the superior efficacy of lenograstim in lymphoma patients could found the basis in the glycosylated nature of this molecule, rather than in biosimilar formulation of filgrastim, with lymphoma patients having a greater previous chemotherapeutic load compared with myeloma and being speculatively more sensitive to the little differences between glycosylated and nonglycosylated formulations of G‐CSF in stem cell mobilization capacity.…”

“…The study was powered on the basis of the primary endpoint, the rate of achievement of the CD34+ cell collection target dose (at least 4 × 10 6 /kg). The sample size calculation was based on our previous study, where the percentage of patients able to reach the planned CD34+ cell dose was 96% with lenograstim and 73% with biosimilar filgrastim both administered at the same dosage of 5 µg/kg/day . To verify the alternative hypothesis (H1) that lenograstim was able to increase by 23% (from 73% to 96%) the percentage of patients reaching the planned CD34+ cell dose even at half the biosimilar filgrastim dosage, against the null hypothesis (H0) of equal proportions, with a power of 80% at a significance level of 5% (with two‐sided test), it was necessary to include in the study a total of 70 patients, 35 for each group.…”

“…However, there are only few retrospective studies comparing lenograstim with biosimilar filgrastim in hematologic patients undergoing PBSC mobilization, while randomized trials focusing exclusively on lymphoma patients are lacking. Our recently published retrospective data suggested that only in lymphoma but not in myeloma patients lenograstim was more effective than biosimilar filgrastim when used at the same dosage of 5 µg/kg for PBSC mobilization, with a comparable safety profile . Based on these considerations, we planned a prospective randomized study comparing, after chemotherapy, lenograstim at the conventional dosage of 5 µg/kg body weight with biosimilar filgrastim at the highest unconventional dosage of 10 µg/kg body weight with the aim to verify the hypothesis of lenograstim superiority in lymphoma patients undergoing PBSC mobilization even at half the dosage.…”