OBJECTIVES: This study aimed to adapt the ADPKD Outcomes Model in order to compare the Chronic Kidney Disease progression and relative costs of Autosomal Dominant Polycystic Kidney Disease (ADPKD)-affected patients treated with JINARC as compared to non-treated patients in Italy. METHODS: Utilising the structure of the ADPKD Outcomes Model adapted to the Italian context, the analysis has simulated the evolution of ADPKD patients over a period of 80 years. The study was performed from both the National Health Service and social perspectives. The ADPKD Outcomes Model is based on a series of annual simulations at the individual patient level that allows clinical evolutions, such as the achievement of end-stage renal disease (ESRD). The model is able to incorporate country-specific pathways for ESRD-affected patients, such as haemodialysis (HD), peritoneal dialysis (PD), transplant and conservative therapy, together with their different costs and mortality rates. Clinical data on treatment effect of tolvaptan were derived from TEMPO 3:4 clinical trial. RESULTS: The results show that tolvaptan is estimated to postpone the time-to-ESRD by a mean of around 3.7 years and increase life expectancy by a mean of 1.6 years. It is predicted that a larger number of ESRD events and deaths could be avoided among treated patients vs non-treated patients (e.g. 346 ESRD events avoided, and 68 deaths for ESRD avoided at 15 years). In addition, the cumulative cost per patient treated who reaches ESRD, compared to non-treated patient, generates overall savings in the medium to long-term (e.g. at 15 years, €16.6 million saved for HD and €2.0 million saved for PD). CONCLUSIONS: The use of JINARC in ADPKD patients permits not only a slowing down in the worsening of the disease, but also an increase in life expectancy and the achievement of a considerable decrease in direct and indirect health costs in the medium to long-term.