The purpose of the trial was to evaluate and describe the long term safety of tolvaptan in participants with autosomal dominant polycystic kidney disease (ADPKD).

This was a Phase 3b trial to evaluate and describe the long term safety of tolvaptan treatment in ADPKD participants with chronic kidney disease (CKD). Eligible participants could enroll into Trial 156-13-211 after completing the follow-up visit(s) of their previous trial (156-13-210, 156-08-271, 156-04-251, or 156-09-290). Renal function was assessed during screening by using historical laboratory values for serum creatinine levels to calculate the estimated glomerular filtration rate (eGFR).

Inclusion Criteria:

• Male and female participants ≥ 18 years with confirmed diagnosis of ADPKD (during participation in prior tolvaptan trials) who have completed and transferred from the double-blind Trial 156-13-210 (12-month period including post treatment follow-up, regardless of whether this was on-treatment or off-treatment), or completed Trial 156-08-271 or a prior tolvaptan trial, or interrupted or discontinued treatment in a prior tolvaptan ADPKD trial other than Trial 156-13-210. Participants may be enrolled with the medical monitor approval, and additional close monitoring may be required at the beginning of the trial.
• eGFR ≥ 20 milliliter (mL)/minute (min)/1.73 meter squared (m^2) within 3 months prior to the baseline visit. Participants who have an eGFR ≤ 20 mL/min/1.73 m^2 may be enrolled with medical monitor approval.

Exclusion Criteria:

• Need for chronic diuretic use
• Hepatic impairment based on liver function abnormalities other than that expected for ADPKD with cystic liver disease
• Women of childbearing potential who do not agree to practice 2 different methods of birth control or remain abstinent during the trial and for 30 days after the last dose of investigational medicinal product (IMP)
• Women who are breast-feeding and/or who have a positive pregnancy test result prior to receiving IMP.
• Participants with contraindications to required trial assessments (contraindications to optional assessments, for example, magnetic resonance imaging [MRI] are not a limitation).
• Participants who in the opinion of the investigator or the medical monitor, have a medical history or medical finding inconsistent with safety or trial compliance

Anonymized Individual participant data (IPD) that underlie the results of this study will be shared with researchers to achieve aims pre-specified in a methodologically sound research proposal. Small studies with less than 25 participants are excluded from data sharing.

Data will be available after marketing approval in global markets, or beginning 1-3 years following article publication. There is no end date to the availability of the data.

Otsuka will share data on an Otsuka-owned remotely accessible data sharing platform with Python and R analytical software. Research requests should be directed to clinicaltransparency@Otsuka-us.com