Prevention and Treatment of Chemotherapy-Induced Neutropenia with the Biosimilar Filgrastim: A Non-Interventional Observational Study of Clinical Practice Patterns

Abstract

Background: Biosimilars are similar but non-identical versions of existing biological drugs. The HEXAFIL study was an observational study that assessed the clinical usage, safety and efficacy of the biosimilar filgrastim in routine clinical practice in Germany. Patients and Methods: A total of 1,337 cancer patients received the biosimilar filgrastim for primary prophylaxis (PP), secondary prophylaxis (SP) or interventional treatment (TX) plus chemotherapy. Data including neutropenic complications and adverse events (AEs) were documented for up to 3 consecutive cycles. Results: In cycle 1, 44.9% of the patients received the biosimilar filgrastim as PP, 31.0% as SP, and 23.6% as TX. Approximately 90% of the patients required no modifications to their chemotherapy regimen, with lower rates among the PP/SP versus the TX patients. Neutropenic complications occurred in 7.9%, 6.9%, and 3.9% of the patients (cycles 1, 2, and 3, respectively). Only 1.8% of the patients experienced febrile neutropenia during cycle 1. Earlier and longer filgrastim treatment reduced grade 3/4 leukopenia and neutropenic complications. The observed safety/tolerability profile was as expected; the most common AE (4.3%) was musculoskeletal back/bone pain. Conclusion: In this observational real-life study of clinical practice, the biosimilar filgrastim was effective and well tolerated, with results consistent with those reported in phase II and phase III trials.

Efficacy and safety of biosimilar filgrastim in primary and secondary prevention of febrile neutropenia

“…During the first cycle of chemotherapy, only 1.8% of patients experienced FN. Tolerance and safety of biosimilar filgrastim was similar to that previously known for this class of drugs; that is, bone and muscle pain were the most common treatment-related adverse events (12).…”

“…The frequency of neutropenia of all grades and grade 4 neutropenia (ANC <0.5x10 3 /µl) were comparable for biosimilar filgrastim and original products (Granulokine ® and Neupogen ® ; Amgen Inc.) (15). Similarly, the incidence of FN did not significantly differ with the biosimilar drug compared to the originators; the incidence was 44% for biosimilar filgrastim and 40% for the original filgrastim (12). On the basis of the present study, it was concluded that biosimilar filgrastim is effective in the prevention of FN and reduces the frequency of unplanned hospitalization in patients with soft tissue sarcomas (15 ) was also found in a non-interventional study (16), in which 77 patients with cancer were treated with biosimilar filgrastim and 25 were treated with the original product.…”

“…No differences in other clinically relevant features (including the incidence of FN, the need for hospitalization due to FN, the incidence of infectious complications, depth and time of the ANC nadir and the normalization of ANC) during the first and all subsequent cycles of treatment were observed (11). In a previous non-interventional observational study involving >1,300 patients undergoing chemotherapy (the HEXAFIL study), the clinical usefulness, efficacy and safety of biosimilar filgrastim was evaluated (12). A large number of patients (44.9%) received biosimilar filgrastim for primary prevention of FN, similar to the present study in which 60% received biosimilar filgrastim for primary prophylaxis.…”

“…A large number of patients (44.9%) received biosimilar filgrastim for primary prevention of FN, similar to the present study in which 60% received biosimilar filgrastim for primary prophylaxis. Approximately 90% of patients could continue chemotherapy without need for treatment modification (i.e., cytostatic dose or time of administration) (12). Complications associated with neutropenia occurred in 7.9, 6.9 and 3.9% of patients at the first, second and third treatment cycle, respectively (12).…”

“…Approximately 90% of patients could continue chemotherapy without need for treatment modification (i.e., cytostatic dose or time of administration) (12). Complications associated with neutropenia occurred in 7.9, 6.9 and 3.9% of patients at the first, second and third treatment cycle, respectively (12). During the first cycle of chemotherapy, only 1.8% of patients experienced FN.…”