A comparative effectiveness study examined clinical outcomes and costs after treatment with a febrile neutropenia therapy vs a biosimilar for patients with non-myeloid cancer undergoing chemotherapy.
The study will be published in the Journal of Managed Care & Specialty Pharmacy (doi:10.18553/jmcp.2018.17447).
Filgrastim is a granulocyte colony-stimulating factor designed to decrease the incidence of febrile neutropenia among patients with non-myeloid cancer undergoing chemotherapy treatment. The biosimilar filgrastim-sndz has been US Food and Drug Administration (FDA) approved since 2015, but limited real-world comparisons of the biosimilar and the reference drug have been conducted.
Lee S Schwartzberg, MD, Vector Oncology and The West Clinic (Memphis, TN), and colleagues compared the febrile neutropenia incidence and assessed overall febrile neutropenia-related health care resource utilization and medical costs among US patients with non-myeloid cancer who received filgrastim-sndz or filgrastim during the first cycle of chemotherapy. The retrospective claims analysis included 3542 patients (filgrastim-sndz, n = 172; filgrastim, n = 3370) who were enrolled in commercial or Medicare Advantage insurance plans from March 2015 through June 2016.
Researchers noted that febrile neutropenia was defined on the basis of diagnosis codes for neutropenia and fever (N/F); neutropenia and infection (N/I); and neutropenia, infection, and fever (N/I/F). The cohorts were adjusted for differences in baseline patient characteristics using the inverse probability of treatment weighting method, and equivalence testing was used to compare the proportion of patients who developed febrile neutropenia between weighted cohorts. After the inverse probability of treatment weighting method was utilized, there were 162 patients in the filgrastim-sndz cohort and 3297 patients in the filgrastim cohort.
Dr Schwartzberg and colleagues found that febrile neutropenia incidence in these weighted cohorts, respectively, was 1.4% vs 0.9% for N/F, 2.3% vs 1.7% for N/I, and 0.0% vs 0.3% for N/I/F.
Mean febrile neutropenia-related total medical costs for all patients who developed febrile neutropenia were $11,977 for N/F, $8040 for N/I, and $21,733 for N/I/F. Researchers noted that the largest proportions of medical costs were inpatient related for all three definitions of febrile neutropenia.
“In this real-world study of patients with non-myeloid cancer undergoing chemotherapy, the incidence of febrile neutropenia was statistically equivalent between individuals treated with filgrastim-sndz vs filgrastim during their first chemotherapy cycle,” authors of the study concluded. “Febrile neutropenia-related health care resource utilization and medical costs among patients who developed febrile neutropenia were substantial.”—Zachary Bessette