Economic and clinical aspects of intravenous versus oral busulfan in adult patients for conditioning prior to HSCT

PURPOSE: Busulfan (BU) used as cytoreductive conditioning prior to hematopoietic stem cell transplantation (HSCT) is available as intravenous (IV) and oral (O) preparation. IV-BU has clinical advantages associated with relevant incremental costs. The aim was to determine the economic impact of IV-BU versus O-BU in adult HSCT recipients from a German health care providers’ perspective. METHODS: A budget-impact model (BIM) including costs and risks for oral mucositis (OM), infection with OM, and hepatic sinusoidal obstruction syndrome (SOS) was developed. Model inputs are literature data comparing clinical effects of IV-BU versus O-BU and German cost data (conditioning therapy, treatment of OM, infections, SOS without/with multiorgan failure) from literature and tariff lists. RESULTS: Base case calculations resulted the following: total costs of adverse events were €86,434 with O-BU and €44,376 with IV-BU for ten patients each. Considering costs of adverse events and drugs, about €5840 for ten patients receiving IV-BU are saved. Sensitivity analyses were conducted in several ways. Cost savings range between €4910 and €12,640 per ten patients for all adverse events and €2070 or €1140 per ten patients considering SOS only. Drug treatment of SOS and treatment of multiorgan failure during severe SOS are major cost drivers. Worst case scenario calculations (assuming −25 % risk of all adverse events for O-BU and +25 % for IV-BU) yield up to €27,570 per ten patients with IV-BU. CONCLUSIONS: Considering costs of adverse events and drugs, IV-BU is the dominant alternative from a German providers’ perspective. For more comprehensive economic evaluations, additional epidemiological data, evidence on clinical outcomes, patient-reported outcomes, and treatment patterns are needed.