Dose-finding Study of New Tolvaptan Formulation in Subjects With ADPKD

To establish pharmacokinetics (PK), pharmacodynamics (PD), and adverse event (AE) profile of tolvaptan administered as the modified-release (MR) formulation in ADPKD subjects. The goals of this trial are two-fold:
    - To directly compare the immediate release (IR) and MR formulations
    - To determine the dose range and dose regimen for MR (dose finding)


Study Type: Interventional
Allocation: Randomized
Endpoint Classification: Pharmacokinetics/Dynamics Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatmen
Official Title: A Multi-center, Parallel-group, Randomized, Double-blind, Placebo-masked, Multiple Dose Trial of Modified-release (MR) and Immediate-release (IR) Tolvaptan in Subjects With Autosomal Dominant Polycystic Kidney Disease (ADPKD)
Enrollment: 25
Study Start Date: October 2010
Study Completion Date: June 2011
Primary Completion Date: June 2011 (Final data collection date for primary outcome measure)

Arms:
- Experimental: 20 mg MR
- Experimental: 40 mg MR
- Experimental: 60 mg MR
- Experimental: 120 mg MR
- Experimental: 120 mg IR