Prevention and treatment of chemotherapy-induced neutropenia with the biosimilar filgrastim: a non-interventional observational study of clinical practice patterns.

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. © 2015 S. Karger GmbH, Freiburg.