| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated  | 
| Autosomal Dominant Polycystic Kidney Disease (ADPKD) | 
 
 
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| MedDRA Classification | 
| E.1.2 Medical condition or disease under investigation | 
| E.1.2 | Version  | 9.1 | 
 
| E.1.2 | Level  | LLT | 
 
| E.1.2 | Classification code  | 10036046 | 
 
 
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| E.1.3 | Condition being studied is a rare disease  |  No  | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial  | 
| To demonstrate whether tolvaptan modifies ADPKD progression as measured by changes from baseline (from  trial 156-04-251) in total kidney volume (TKV) and renal function. | 
 
 
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| E.2.2 | Secondary objectives of the trial  | 
| To determine whether, for placebo-treated subjects from trial 156-04-251, the annual rate of change (slope) in  TKV and renal function changes during the crossover from placebo to tolvaptan treatment.  To explore exposure response relationship among all subjects enrolled in this trial for changes in TKV, renal  function and hypertension. | 
 
 
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| E.2.3 | Trial contains a sub-study  |  No  | 
| E.3 | Principal inclusion criteria  | 
| 1) Successful completion (protocol defined completer without early termination) of a Phase 1, 2, or 3 tolvaptan  ADPKD or renal impairment trial, with a confirmed diagnosis of ADPKD.  2) Estimated GFR ≥30 ml/min/1.73m2 within 30 days prior to enrollment (calculated using the IDMS-traceable  modification of diet in renal disease [4 parameter MDRD] equation with correction for gender and race).  Subjects with lower estimated GFR (eGFR) may be permitted with documented medical monitor approval prior  to enrollment. | 
 
 
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| E.4 | Principal exclusion criteria | 
| • Safety contraindications including: non-compliance with therapies, reproductive precautions, unawareness of thirst, severe allergic reactions to compounds with similar chemical structure as tolvaptan  • Contraindications to or interference with MRI assessments  • Concurrent conditions or taking therapies likely to confound endpoint assessments or prevent completion of the trial (Efficacy Analysis Exclusion Only) | 
 
 
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| E.5 End points | 
| E.5.1 | Primary end point(s) | 
| The two primary efficacy endpoints analyzed will be in subjects continuing from protocol 156-04-251 comparing  those previously treated with tolvaptan (combining all doses) to those subjects previously treated with placebo,  disease modification as measured by:  Percent change from 156-04-251 baseline in Total kidney volume (TKV) at Month 24 in trial 156-08-271 as  compared to the percent change in TKV at 156-04-251 Month 36 measured by magnetic resonance imaging  (MRI)  then  Change in renal function (100x1/Serum Creatinine mg/dl) at Month 24 in trial 156-08-27) as compared to change  in renal function at Month 36 in protocol 156-08-251, both relative to 156-04-251 end of titration baseline. | 
 
 
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| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis |  No  | 
| E.6.2 | Prophylaxis |  No  | 
| E.6.3 | Therapy |  No  | 
| E.6.4 | Safety |  Yes  | 
| E.6.5 | Efficacy |  Yes  | 
| E.6.6 | Pharmacokinetic |  Yes  | 
| E.6.7 | Pharmacodynamic |  Yes  | 
| E.6.8 | Bioequivalence |  No  | 
| E.6.9 | Dose response |  No  | 
| E.6.10 | Pharmacogenetic |  No  | 
| E.6.11 | Pharmacogenomic |  No  | 
| E.6.12 | Pharmacoeconomic |  No  | 
| E.6.13 | Others |  No  | 
| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) |  No  | 
| E.7.1.1 | First administration to humans |  No  | 
| E.7.1.2 | Bioequivalence study |  No  | 
| E.7.1.3 | Other |  No  | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) |  No  | 
| E.7.3 | Therapeutic confirmatory (Phase III) |  Yes  | 
| E.7.4 | Therapeutic use (Phase IV) |  No  | 
| E.8 Design of the trial | 
| E.8.1 | Controlled |  No  | 
| E.8.1.1 | Randomised |  No  | 
| E.8.1.2 | Open |  No  | 
| E.8.1.3 | Single blind |  No  | 
| E.8.1.4 | Double blind  |  No  | 
| E.8.1.5 | Parallel group |  No  | 
| E.8.1.6 | Cross over  |  No  | 
| E.8.1.7 | Other |  Yes  | 
| E.8.1.7.1 | Other trial design description | 
| In Aperto non randomizzato. Regimi di Trattamento: 45/15, 60/30 e 90/30 mg di tolvaptan | 
 
 
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| E.8.2 |  Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) |  No  | 
| E.8.2.2 | Placebo  |  No  | 
| E.8.2.3 | Other |  No  | 
| E.8.3 | 
                                The trial involves single site in the Member State concerned
                             |  No  | 
| E.8.4 |  The trial involves multiple sites in the Member State concerned  |  Yes  | 
| E.8.4.1 | Number of sites anticipated in Member State concerned | 5 | 
| E.8.5 | The trial involves multiple Member States |  Yes  | 
| E.8.5.1 | Number of sites anticipated in the EEA | 80 | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.1 | Trial being conducted both within and outside the EEA |  Yes  | 
| E.8.6.2 | Trial being conducted completely outside of the EEA |  Information not present in EudraCT  | 
| E.8.6.3 | If E.8.6.1 or E.8.6.2 are Yes, specify the regions in which trial sites are planned | 
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| E.8.7 | Trial has a data monitoring committee |  No  | 
| E.8.8 | 
                        Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial
                     |  | 
| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.1 | In the Member State concerned years | 5 | 
| E.8.9.1 | In the Member State concerned months | 0 | 
| E.8.9.1 | In the Member State concerned days | 0 | 
| E.8.9.2 | In all countries concerned by the trial years | 5 | 
| E.8.9.2 | In all countries concerned by the trial months | 0 | 
| E.8.9.2 | In all countries concerned by the trial days | 0 |