Budget Impact Analysis of Switching Chemotherapy Patients Using Granulocyte Colony-Stimulating Factors (G-CSFs) from Pegfilgrastim to Short-Acting G-CSFs in the United States

Introduction: Neutropenia is a common complication in patients receiving myelosuppressive chemotherapy for nonmyeloid malignancies. Severe and febrile neutropenia (FN) are associated with prolonged hospitalization, serious infections and broad-spectrum antibiotic use, decreased quality of life, and increased medical costs and mortality. G-CSFs are often administered to reduce incidence, severity, and duration of FN in chemotherapy patients. While pegfilgrastim is dosed once per chemotherapy cycle (14-day efficacy), data suggest the average duration of short-acting G-CSF use is considerably shorter than 14 days. This analysis estimated the budget impact of increasing utilization of short-acting G-CSFs (filgrastim [Neupogen®], tbo-filgrastim [Granix®, a filgrastim follow-on biologic], and filgrastim-sndz [Zarxio®, a filgrastim biosimilar]) while decreasing utilization of long-acting pegfilgrastim (Neulasta®) products for patients with nonmyeloid malignancies treated with myelosuppressive chemotherapy from a US payer perspective.

Methods: An interactive budget impact model was developed to estimate changes in drug and administration costs associated with a projected 10% reduction in pegfilgrastim market share (an estimated 7.6% of the total G-CSF market) and an equal increase split evenly across short-acting product lines (approximately 1/3 allocated to 300-mcg products and 2/3 allocated to 480-mg products within product lines) for patients with nonmyeloid malignancies treated with myelosuppressive chemotherapy within a 1-million-member health plan. Patient self-administration at home was assumed for 40% of patients receiving short-acting G-CSFs and 10% of patients receiving long-acting agents, with the remaining administered by health care provider (HCP) in an office or other outpatient setting. Patients receiving short-acting G-CSFs were assumed to require 10 doses per chemotherapy cycle, with long-acting agents given once per cycle. Self-administered products were purchased via the patient's pharmacy benefit at an assumed Tier 3 formulary status with a patient copay of $57 per prescription. HCP-administered products were assumed to be primarily (85%) purchased through the patient's medical benefit and provided on site, while a small proportion of patients (15%) were assumed to purchase G-CSFs through their pharmacy benefit to be HCP administered; in both cases, administration costs for injections were included, and with pharmacy benefit adjudication, a patient drug cost-share was applied ($57 per prescription). Base-case data were derived from publicly available resources. The budget impact was calculated using a 1-year time horizon, along with the difference in effective per-member per-year (PMPY) cost between current and proposed scenarios; univariate sensitivity analyses were conducted.

Results: The effective annual per-patient plan drug costs ranged from $12,288 to $30,772 for short-acting G-CSFs and from $27,013 to $33,698 for pegfilgrastim (depending on dose and adjudication channel per product). The estimated total effective annual plan cost prior to the utilization shift was $425,518,352 (PMPY = $425.53) and was $419,985,093 (PMPY = $419.99) following the shift. The home administration budget increased by $5,793,056, while the HCP administration budget decreased by $11,326,314, for an overall annual cost savings of $5,533,259 (PMPY = $5.54). Per-patient savings for tbo-filgrastim and filgrastim-sndz ranged from 16.1% to 54.5%, depending on dose and adjudication channel. The model was most sensitive to changes in pegfilgrastim acquisition cost and the patient's medical benefit cost-share.

Conclusions: Budget impact analyses examine the financial impact associated with the introduction of new treatments or shifting existing treatment patterns to help decision makers determine how best to allocate resources. Without considering additional impacts of health plan contracted rates and manufacturer rebates, the annual plan per-patient drug cost for tbo-filgrastim and filgrastim-sndz formulations were substantially less expensive than pegfilgrastim for an average treatment cycle. This analysis estimated an annual US health plan cost savings of over $5.5 million or more than $5.50 PMPY following an overall 7.6% utilization shift from long-acting to short-acting G-CSFs.