Ali McBride, PharmD, MS, BCPS, clinical coordinator of hematology/oncology at the University of Arizona Cancer Center, presented the latest developments on the first FDA-approved biosimilar, Zarxio® (filgrastim-sndz).
Zarxio (filgrastim-sndz) is a recently approved colony-stimulating factor and a biosimilar to the reference product, Neupogen (filgrastim). Zarxio was approved through the 351 approval pathway and is indicated for patients receiving myelosuppressive chemotherapy, patients with acute myeloid leukemia receiving induction or consolidation chemotherapy, patients with cancer undergoing bone marrow transplantation, patients undergoing peripheral blood progenitor-cell collection and therapy, and patients with severe chronic neutropenia.1
Zarxio met all 5 biosimilar standards: demonstrating high similarity in analytical data, animal studies, and clinical studies while maintaining the same mechanism of action and route of administration, dosage forms, and strength as the reference product. Biosimilarity of Zarxio to Neupogen was confirmed by the PIONEER study and a pharmacokinetic/pharmacodynamics study that reported no difference in safety, purity, and potency between the 2 products.1
The PIONEER study was a randomized, double-blind comparative study that analyzed the efficacy and safety between Zarxio and Neupogen for 24 weeks.2 The primary end point tested was comparative equivalency assessment of mean duration of severe neutropenia between Zarxio and Neupogen at cycle 1. A total of 218 patients with breast cancer were randomized and received 6 cycles of Taxotere (docetaxel), Adriamycin (doxorubicin), and cyclophosphamide, and received either Zarxio or Neupogen daily starting on day 2 of each cycle.2 In cycle 1, the mean duration of severe neutropenia (DSN) was 1.17 days with Zarxio versus 1.2 days with Neupogen (DSN difference for Neupogen minus Zarxio [90% confidence interval] 0.04 days). The study also determined that the safety profile of Zarxio compared with Neupogen was not markedly different, and equivalence between products was demonstrated.
McBride A. Product theater presentation at ASHP Midyear Clinical Meeting. Las Vegas, NV; December 2016.
- ZARXIO Prescribing Information. Sandoz Inc. March 2016.
- Blackwell K, et al. Ann Oncol. 2015; 26(9):1948-1953.