The protocol will extend the understanding of the efficacy and safety of tolvaptan treatment in ADPKD patients with late stage 2 to early stage 4 CKD (chronic kidney disease).~This trial will compare the efficacy of tolvaptan treatment in reducing the annualized change in estimated glomerular filtration rate (eGFR) from pre-treatment baseline to post-treatment follow-up, as compared with placebo, in subjects who tolerate tolvaptan during an initial run-in period. The change in eGFR, calculated by the Chronic Kidney Disease-Epidemiology (CKD-EPI) formula, will provide kidney function data that are complementary to the data demonstrating the benefits previously observed primarily in ADPKD subjects with earlier stages of disease.~Also, it will compare the efficacy of tolvaptan treatment in reducing the decline of annualized eGFR slope, as compared with placebo, in this type of subjects. Finally, it will compare the overall and hepatic safety profile of tolvaptan with placebo and to compare incidence of ADPKD complications (outcomes) during the trial
The purpose of the study is to determine whether tolvaptan is effective and safe for the treatment of late-stage chronic kidney disease due to autosomal dominant polycystic kidney disease (ADPKD)