Sandoz biosimilar filgrastim was approved in the EU in 2009 and in 2015 was the first biosimilar approved in the US. These authorisations were based on ‘totality of evidence’, considering data from the state of the art analytical characterization and comparability exercises, the PK/PD studies, and confirmatory phase III clinical study in the most sensitive patient population: breast cancer patients undergoing myelosuppressive chemotherapy. In both the EU and US, approval was granted for the same indications as the reference biologic (including stem cell mobilisation [SCM] and severe chronic neutropenia [SCN]), on the basis of extrapolation, with no clinical trials conducted at the time of approval.
This review aims to discuss clinical evidence for Sandoz biosimilar filgrastim in all approved indications, including the Phase III confirmatory studies in CIN, post-approval clinical studies in SCM and real-world experience.
A narrative review was undertaken to provide an evidence-based summary of the available clinical studies and real-world evidence on the efficacy and safety of Sandoz biosimilar filgrastim in CIN prophylaxis for different tumour types, autologous and allogeneic SCM, and SCN.
CIN: The registration trials, confirmatory to the totality of evidence, supported the approval of Sandoz biosimilar filgrastim in the EU and US. Post-approval studies have provided further evidence of the efficacy and safety of Sandoz biosimilar filgrastim. MONITOR-GCSF, a multicentre, prospective, observational study in cancer patients (n = 1447) receiving Sandoz biosimilar filgrastim for CIN prophylaxis, reported a total of 4271 events in 777 patients (53.7%) with bone pain the most common (24.7%).1 There were no neutropenia- or biosimilar filgrastim-related deaths. MONITOR-GCSF sub-analyses have provided evidence for the efficacy and safety profile of Sandoz biosimilar filgrastim in different tumour types, such as DLBCL and NSCLC.2,3
SCM: Overall, data from studies of autologous SCM show that the efficacy and safety of biosimilar filgrastim matches the known profile of reference filgrastim, and results are similar when reference filgrastim is included as a comparator. A retrospective analysis in 51 healthy sibling donors showed effective mobilization without notable AEs after 2 years’ follow-up.4 Evidence is also emerging in allogeneic SCM, such as a study with the largest donor cohort (n = 244) reported to date.5 After a mean follow-up of 433 days, efficacy and safety of biosimilar filgrastim were consistent with previous reports, and no haematological or solid malignancies occurred.
SCN: The European Branch of the SCN International Registry has followed patients with SCN since 1994. While final analysis is ongoing, no serious AEs have been reported in patients receiving Sandoz biosimilar filgrastim.
There is now a decade of clinical experience with Sandoz biosimilar filgrastim, including over 21 million patient-days of exposure. This experience is reassuring regarding the safety and efficacy of Sandoz biosimilar filgrastim in patients with DLBCL, and in allogeneic SCM, and shows that extrapolation for biosimilars is based on strong scientific evidence and principles.
References: 1. Gascón et al. Support Care Cancer 2016;24:911–25; 2. Gascón et al. Eur J Haematol. 2018;100:241–6; 3. Aapro et al. Ann Oncol. 2017;28(suppl 10):524P; 4. Taylor et al. Bone Marrow Transplant 2017;52(S1):S145. 5. Becker et al. Transfusion. 2016;56:3055–64.