Abstract
The objectives of this study were to simulate for the European Union G5 countries the potential cost savings of converting patients from originator granulocyte colony-stimulating factor (G-CSF) filgrastim and pegfilgrastim to a biosimilar filgrastim, to evaluate how reallocating these savings could increase patient access to antineoplastic therapy, and to estimate the number of patients needed to convert to provide antineoplastic treatment to one patient.
Three models were built: (1) to estimate the costs of using originator G-CSFs and the savings generated from switching to a biosimilar G-CSF, (2) to estimate the incremental number of patients who could be provided antineoplastic therapy-rituximab or trastuzumab-in a hypothetical panel of 10,000 patients with cancer, and (3) to calculate the number of patients needed to convert to provide access to anticancer therapy. Scenarios were developed in which the rate of conversion was varied to estimate the effect on total cost savings. This study took the perspective of the payer in the European Union.
The savings associated with the biosimilar filgrastim over the originator filgrastim ranged from €785 (day 4) to €2747 (day 14) and increased with longer duration of therapy. By contrast, the savings associated with the biosimilar filgrastim over pegfilgrastim decreased over time, ranging from €6199 (day 4) to €471 (day 14). In a hypothetical panel of 10,000 patients with cancer, the savings associated with the biosimilar filgrastim over the originator filgrastim and the expanded access to antineoplastic therapy improved over time, irrespective of conversion rates. Conversely, in the same hypothetical panel, the savings associated with the biosimilar filgrastim over pegfilgrastim reduced over time, irrespective of conversion rates, along with the expanded access to antineoplastic treatment. Under conversion of the originator filgrastim to the biosimilar filgrastim, the number needed to convert to expand access to rituximab ranged from 4 to 14 patients, and the number needed to convert to expand access to trastuzumab ranged from 11 to 38 patients. Under conversion of pegfilgrastim to the biosimilar filgrastim, the number needed to convert to expand access to rituximab ranged from 2 to 24 patients, and the number needed to convert to expand access to trastuzumab ranged from 5 to 63 patients.
Use of biosimilar G-CSFs for supportive cancer care could yield potential cost savings and improve patient access to antineoplastic therapy in a budget neutral way-a financial effect with an ethical perspective.