Budget Impact Analysis of Liposomal Amphotericin B and Amphotericin B Lipid Complex in the Treatment of Invasive Fungal Infections in the United States

Abstract

Liposomal amphotericin B (L-AMB) and amphotericin B lipid complex (ABLC) are both indicated for treating invasive fungal infections (IFIs) caused by Aspergillus, Candida and Cryptococcus spp. among patients who are refractory to or intolerant of conventional amphotericin B (CAB). Prior studies have suggested similar efficacies but differences in adverse event (AE) profiles between L-AMB and ABLC. Our objective was to conduct a cost-minimisation and budget impact analysis for the treatment of IFIs with L-AMB and ABLC in a US hospital setting. A Microsoft® Excel-based budget impact model was developed to estimate the costs associated with using L-AMB and ABLC for the treatment of adult patients with Aspergillus, Candida and Cryptococcus spp. infections, who are refractory to or intolerant of CAB, during a hospital stay. The model was built from a hospital perspective, and included drug costs of L-AMB and ABLC, and costs for treating drug-related AEs (i.e. nephrotoxicity with/without dialysis, infusion-related reactions, anaphylaxis, hypomagnesaemia and hypokalaemia). Average sales price was used as the drug cost estimate in the base-case analyses. The treatment duration and rates of AEs for L-AMB and ABLC were mainly obtained from a retrospective study of these two drugs in the target population using the Cerner Health Facts data. Treatment costs of AEs were obtained from the publicly available sources. The budget impact ($US, year 2011 values) was evaluated for a hypothetical hospital with 100 administrations where L-AMB and ABLC are used for the treatment of the target population by changing the market share of L-AMB and ABLC from 32/68% to an anticipated market share of 60/40% in the base-case analysis. Sensitivity analyses were conducted by varying drug costs, rates of AEs, costs of AEs and anticipated market shares of L-AMB and ABLC. The estimated per-patient cost per hospital episode associated with L-AMB and ABLC use were $US14,563 and $US16,748, respectively. Cost of AEs accounted for 68.7% of the costs for L-AMB and 85.4% for ABLC. In a hypothetical hospital with 100 annual admissions of patients using these two drugs for IFIs, changing the market shares from 32/68% for L-AMB and ABLC, respectively, to 60/40% yielded a 3.8% cost reduction, which corresponded to an absolute cost savings of $US61,191. Sensitivity analyses indicated that the results were robust to changes in input parameter values in most cases. This study suggests that hospitals can realize cost savings by substituting L-AMB for ABLC in the treatment of IFIs. The cost savings are driven by the lower rates of AEs associated with L-AMB use compared with ABLC.