Adapting a global cost-effectiveness model to local country requirements: posaconazole case study

Many countries have various requirements for local economic analyses to assess the value of a new health technology and/or to secure reimbursement. This study presents a case study of an economic model developed to assess the cost-effectiveness of posaconazole vs standard azole therapy (fluconazole/itraconazole) to prevent invasive fungal infections (IFIs), which was adapted by at least 11 countries.

Modeling techniques were used to assess the cost-effectiveness of posaconazole vs fluconazole/itraconazole as IFI prophylaxis in patients with acute myelogenous leukemia or myelodysplastic syndromes and chemotherapy-induced neutropenia. For the core model, the probabilities of experiencing an IFI, IFI-related death, and death from other causes were estimated from clinical trial data. Long-term mortality, drug costs, and IFI treatment costs were obtained from secondary sources. Locally changed parameters were probabilities of long-term death and survival, currency, drug costs, health utility, IFI treatment costs, and discount rate.

Locally adapted cost-effective modeling studies indicate that prophylaxis with posaconazole, compared with fluconazole/itraconazole, prolongs survival, and, in most countries, is cost-saving. In all countries, the model predicted that prophylaxis with posaconazole would be associated with an increase in life-years, with increases ranging from 0.016-0.1 life-year saved. In all countries, use of the model led to posaconazole being approved by the appropriate reimbursement authority.

The study did not have power to detect differences between posaconazole and fluconazole or itraconazole separately. The risk of death after 100 days was assumed to be equal for those who did and did not develop an IFI, and equal probabilities of IFI-related and other death during the trial period were used for both groups.

A core economic model was successfully adapted locally by several countries. The model showed that posaconazole was cost-saving or cost-effective vs fluconazole/itraconazole and led to positive reimbursement listings.