A COST-EFFECTIVENESS ANALYSIS OF TOLVAPTAN TO SLOW PROGRESSION OF AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

Purpose:  In the Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and its Outcomes (TEMPO) trial, tolvaptan significantly reduced intra-renal cyst volume growth and loss of kidney function in patients with autosomal dominant polycystic kidney disease (ADPKD).  It is unknown how these benefits relate to longer-term outcomes including progression to end-stage renal disease (ESRD) and mortality, and whether tolvaptan treatment is cost-effective.

Method:   We developed a decision-analytic model of tolvaptan therapy in 40 year-olds with early ADPKD to determine the expected slowing of progression to ESRD, reduction in mortality, and cost-effectiveness of tolvaptan therapy.  Main outcomes were median age at ESRD onset, life expectancy, discounted quality adjusted life years (QALYs) and lifetime costs (2010 USD), and incremental cost-effectiveness ratios (ICERs). In the base case, we assumed that the clinical benefit observed in the TEMPO trial persists until patients reach ESRD. 

Result:   In a base case simulation, tolvaptan prolonged the median age at ESRD onset by 6.5 years and increased life expectancy by 2.6 years.  At a drug cost of $5,760 per month, tolvaptan therapy for patients with ADPKD cost $744,100 per QALY gained compared to standard care. Tolvaptan’s cost per QALY gained is even higher for patients with ADPKD that progresses more slowly.

Conclusion: Assuming that tolvaptan’s benefits persist longer term, it may slow progression to ESRD and reduce mortality.  However, barring a 94-96% reduction in the price of tolvaptan, its cost-effectiveness does not compare favorably to many other commonly accepted medical interventions.