Initial combination therapy for patients with pulmonary arterial hypertension (PAH). a budget impact analysis from the perspective of the italian national healthcare system

Background: Initial combination therapy in patients with pulmonary arterial hypertension (PAH) WHO functional class (FC) II or III has demonstrated clinical benefits over initial monotherapy. The objective of this study is to compare the financial impact of initial combination therapy with initial monotherapy for incident patients with PAH in Italy. Methods: A 3-year budget impact model compared a ‘status quo’ scenario of initial monotherapy with an endothelin receptor antagonist (ERA), phosphodiesterase 5 inhibitor (PDE5i) or prostanoid, with a ‘new’ scenario involving initial combination therapy, using Italian national healthcare system (NHS) data for incident patients with PAH WHO FC II or III. The hospitalisation hazard ratio (HHR) from the AMBITION study and expert panel advice on therapy use were employed. Univariate sensitivity analyses were performed. Results: A difference in costs of €16,070 favouring the ‘new’ scenario (initial combination therapy) was observed, and attributed to 101 fewer hospitalisations over 3 years. Sensitivity analyses showed that costs were driven by the proportion of patients receiving ERAs versus PDE5i, hospitalisation costs and prostanoid dose. Conclusion: Initial combination therapy instead of monotherapy could reduce the number and cost of hospitalisations without an increase in the total costs to the Italian NHS.