Cost-effectiveness analysis of combination antifungal therapy with voriconazole and anidulafungin versus voriconazole monotherapy for primary treatment of invasive aspergillosis in Spain.

OBJECTIVE: According to a recent randomized, double-blind clinical trial comparing the combination of voriconazole and anidulafungin (VOR+ANI) with VOR monotherapy for invasive aspergillosis (IA) in patients with hematologic disease or with hematopoietic stem cell transplant, mortality was lower after 6 weeks with VOR+ANI than with VOR monotherapy in a post hoc analysis of patients with galactomannan-based IA. The objective of this study was to compare the cost-effectiveness of VOR+ANI with VOR, from the perspective of hospitals in the Spanish National Health System. METHODS: An economic model with deterministic and probabilistic analyses was used to determine costs per life-year gained (LYG) for VOR+ANI versus VOR in patients with galactomannan-based IA. Mortality, adverse event rates, and life expectancy were obtained from clinical trial data. The costs (in 2015 euros [€]) of the drugs and the adverse event-related costs were obtained from Spanish sources. A Tornado plot and a Monte Carlo simulation (1,000 iterations) were used to assess uncertainty of all model variables. RESULTS: According to the deterministic analysis, for each patient treated with VOR+ANI compared with VOR monotherapy, there would be a total of 0.348 LYG (2.529 vs 2.181 years, respectively) at an incremental cost of €5,493 (€17,902 vs €12,409, respectively). Consequently, the additional cost per LYG with VOR+ANI compared with VOR would be €15,785. Deterministic sensitivity analyses confirmed the robustness of these findings. In the probabilistic analysis, the cost per LYG with VOR+ANI was €15,774 (95% confidence interval: €15,763-16,692). The probability of VOR+ANI being cost-effective compared with VOR was estimated at 82.5% and 91.9%, based on local cost-effectiveness thresholds of €30,000 and €45,000, respectively. CONCLUSION: According to the present economic study, combination therapy with VOR+ANI is cost-effective as primary therapy of IA in galactomannan-positive patients in Spain who have hematologic disease or hematopoietic stem cell transplant, compared with VOR monotherapy.

Economic evaluation of azoles as primary prophylaxis for the prevention of invasive fungal infections in Spanish patients undergoing allogeneic haematopoietic stem cell transplant.

Patients undergoing allogeneic haematopoietic stem cell transplantation (alloHSCT) are at risk of developing invasive fungal infections (IFIs). Even with introduction of oral triazole antifungal agents (fluconazole, itraconazole, posaconazole and voriconazole) IFI-associated morbidity and mortality rates and economic burden remain high. Despite their proven efficacy, it is currently unknown which is the most cost-effective antifungal prophylaxis (AFP) agent. To determine the costs and outcomes associated with AFP, a decision-analytic model was used to simulate treatment in a hypothetical cohort of 1000 patients undergoing alloHSCT from the perspective of the Spanish National Health System. Generic itraconazole was the least costly AFP (€162) relative to fluconazole (€500), posaconazole oral suspension (€8628) or voriconazole (€6850). Compared with posaconazole, voriconazole was associated with the lowest number of breakthrough IFIs (36 vs 60); thus, the model predicted fewer deaths from breakthrough IFI for voriconazole (24) than posaconazole (33), and the lowest predicted costs associated with other licensed antifungal treatment and IFI treatment in a cohort of 1000. Voriconazole resulted in cost savings of €4707 per patient compared with posaconazole. Itraconazole demonstrated a high probability of being cost-effective. As primary AFP in alloHSCT patients 180 days posttransplant, voriconazole was more likely to be cost-effective than posaconazole regarding cost per additional IFI and additional death avoided.

Cost analysis of voriconazole versus liposomal amphotericin B for primary therapy of invasive aspergillosis among patients with haematological disorders in Germany and Spain.

BACKGROUND: The current healthcare climate demands pharmacoeconomic evaluations for different treatment strategies incorporating drug acquisition costs, costs incurred for hospitalisation, drug administration and preparation, diagnostic and laboratory testing and drug-related adverse events (AEs). Here we evaluate the pharmacoeconomics of voriconazole versus liposomal amphotericin B as first-line therapies for invasive aspergillosis (IA) in patients with haematological malignancy and prolonged neutropenia or who were undergoing haematopoietic stem-cell transplantation in Germany or Spain. METHODS: A decision analytic model based on a decision tree was constructed to estimate the potential treatment costs of voriconazole versus liposomal amphotericin B. Each model pathway was defined by the probability of an event occurring and the costs of clinical outcomes. Outcome probabilities and cost inputs were derived from the published literature, clinical trials, expert panels and local database costs. In the base case, patients who failed to respond to first-line therapy were assumed to experience a single switch between comparator drugs or the other drug was added as second-line treatment. Base-case evaluation included only drug-management costs and additional hospitalisation costs due to severe AEs associated with first- and second-line therapies. Sensitivity analyses were conducted to assess the robustness of the results. Cost estimates were inflated to 2011 euros (€). RESULTS: Based on clinical trial success rates of 52.8% (voriconazole) and 50.0% (liposomal amphotericin B), voriconazole had lower total treatment costs compared with liposomal amphotericin B in both Germany (€ 12,256 versus € 18,133; length of therapy [LOT] = 10-day intravenous [IV] + 5-day oral voriconazole and 15-day IV liposomal amphotericin B) and Spain (€ 8,032 versus € 10,516; LOT = 7-day IV + 8-day oral voriconazole and 15-day IV liposomal amphotericin B). Assuming the same efficacy (50.0%) in first-line therapy, voriconazole maintained a lower total treatment cost compared with liposomal amphotericin B. Cost savings were primarily due to the lower drug acquisition costs and shorter IV LOT associated with voriconazole. Sensitivity analyses showed that the results were sensitive to drug price, particularly the cost of liposomal amphotericin B. CONCLUSIONS: Voriconazole is likely to be cost-saving compared with liposomal amphotericin B when used as a first-line treatment for IA in Germany and Spain.