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 ((SIC) 162) relative to fluconazole ((SIC) 500), posaconazole oral suspension ((SIC) 8628) or voriconazole ((SIC) 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 (SIC) 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.