Pb2416: efficacy and safety of biosimilar pegfilgrastim after autologous stem cell transplant: a comparative study with biosimilar filgrastim, lenograstim and originator pegfilgrastim

Topic: 22. Stem cell transplantation - Clinical Background: Biosimilar Pegfilgrastim has been approved for prophylaxis of severe neutropenia duration and febrile neutropenia in cancer patients, including those affected by hematologic malignancies. However, poor data have been so far published among patients undergoing both allogeneic and autologous hematopoietic stem cell transplant. Aims: To evaluate efficacy and the safety of biosimilar Pegfilgrastim when used patients undergoing autologous hematopoietic stem cell transplant. Methods: From June 2021 to December 2022, 53 consecutive adult patients with hematologic malignancies (Plasma cell disorders n=38; Non Hodgkin and Hodgkin’s lymphomas n=15) underwent autologous hematopoietic stem cell transplant (ASCT) in our Institution. Biosimilar Pegfilgrastim was given at the dosage of 6 mg single dose at day 3 after infusion of stem cells. Hematologic recovery after ASCT was defined as an absolute neutrophilis count upper than 0.5 x 109/L and a platelets count upper than 20 x 109/L in three consecutive checks. This cohort of patients was compared with three historical cohorts of patients in our Institution: a) 392 consecutive adult patients treated with biosimilar Filgrastim at dosage of 5 mcg/Kg daily given from day 3 after infusion from March 2013 to May 2021; b) 99 consecutive adult patients treated with Lenograstim at dosage of 5 mcg/Kg daily given from day 3 after infusion from January 2009 to February 2013; c) 60 consecutive adult patients treated with originator peg-filgrastim at dosage of 6 mg single dose at day 3 after infusion from March 2006 to December 2008. Results: The four patient cohorts were similar for all baseline features analyzed, even if in the cohort of patient treated with biosimilar pegfilgrastim were older, more frequently diagnosed as myeloma and received a significant lower number of CD34+/Kg cells. We analyzed the time of hematologic recovery after stem cell infusion, the occurrence of fever of unknown origin (FUO) in neutropenia, documented infectious episodes and needing of intravenous antibiotics, number of red blood and platelet transfusions, the days of hospitalization and the transplant-related mortality (TRM). The results of the study show a significantly shorter time to neutrophilis and platelet recovery (P<0.001) in the cohort of patients treated with both biosimilar and originator Pegfilgrastim, whereas no difference was observed among the other two groups. Moreover, patients treated with biosimilar Pefilgrastim showed a shorter hospitalization time (P<0.001) and a lower transfusion need (P<0.001) compared with other groups of patients. As for the other analyzed parameters, we did observe a similar incidence of FUO episodes (P=0.055), microbiologically documented infections (P=0.607), needing of intravenous antibiotics (P=0.778), and TRM (P=0.683). No difference in terms of drug-related adverse events was observed in the four patient cohorts with no reported serious adverse events. Similar results were obtained performing two separate sub-analysis only for lymphoma or myeloma patients. Summary/Conclusion: Despite the limitations due to the non-randomized nature of the study, from our data biosimilar Pegfilgrastim seems to be substantially equivalent in terms of efficacy to the originator one and superior than Lenograstim and biosimilar Filgrastim in terms of hematologic recovery, when used for hematological recovery after ASCT in adult patients with hematologic malignancies. Keywords: Pegfilgrastim, G-CSF, Autologous peripheral blood stem cell tansplantati