This study evaluated whether or not tolvaptan is potentially beneficial, while maintaining an adequate safety profile, by reducing the rate of total kidney volume increase, while impacting the onset, severity, and progression of other important consequences of ADPKD.
During the 3-week titration phase, tolvaptan or placebo was titrated in weekly intervals from lowest to highest tolerated levels given in split-dose regimens of 45/15 mg, 60/30 mg and 90/30 mg orally upon awakening and approximately 9 hours later. As soon as a subject could not tolerate a given dose, the titration phase was over and the maintenance phase began at the dose level tolerated. The maintenance phase lasted to Month 36. Subjects were able to titrate down at any point during the study. Subjects were able to titrate up during the maintenance phase with Medical Monitor approval.
