A Phase 3 interventional study of Tolvaptan Suspension and Tolvaptan Tablets in Autosomal Recessive Polycystic Kidney (ARPKD), sponsored by Otsuka Pharmaceutical Development & Commercialization, Inc.. Recruiting at 23 sites in 6 countries. Open to participants aged 28 Days to 18 Years. Per ClinicalTrials.gov, last updated 2026-10-23.
Sponsored by Otsuka Pharmaceutical Development & Commercialization, Inc. (part of Otsuka Holdings Co., Ltd.) · Phase 3, Interventional, and Treatment
To evaluate the pharmacodynamics and safety of tolvaptan in pediatric subjects with ARPKD
This study is a multinational, multicenter, open-label, non-randomized trial. The study consist of three periods: Screening Period, Treatment period and Follow-up period.
Tolvaptan has been demonstrated to delay the decline of kidney function in adults with rapidly progressing ADPKD (CKD stages 1 to 4), a closely related indication to ARPKD, as measured by estimated glomerular filtration rate (eGFR) and Total Kidney Volume (TKV).
Participants in this study will be assigned to tolvaptan and followed for 24 months over the course of the study.
The overall trial duration is expected to be approximately 5 years.
59 studies on the registry are indexed under Polycystic Kidney Diseases; 12 are open to participants now.
This study's planned enrollment of 20 is below the median of 42 across 36 interventional studies indexed under Polycystic Kidney Diseases.
Browse Polycystic Kidney Diseases studies →Otsuka Pharmaceutical Development & Commercialization, Inc. is the lead sponsor of 295 studies on the registry; 18 are open to participants now.
Of its 106 completed or terminated interventional studies of FDA-regulated products, 71 (67%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Subjects who do not agree to remain abstinent or assent to use a combination of 2 of the following highly effective methods for at least 28 days before the first dose of IMP, during the trial (including during IMP dose interruptions), and for at least 30 days after the last dose of IMP:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Tolvaptan suspension will be administered orally or via feeding/nasogastric tube at doses of 0.15 mg/kg once daily in the AM, 0.30 mg/kg once daily in the AM, 0.5 mg/kg once daily in the AM, 0.75 mg/kg split dose (0.5 mg/kg AM and 0.25 mg/kg 8 hours later), and 1 mg/kg split dose (0.67 mg/kg AM and 0.33 mg/kg 8 hours later) based on age. Treatment duration is 24 months.
Drug: Tolvaptan Suspension
Tolvaptan tablets will be administered orally as split-dose regimens (15/7.5 mg, 30/15 mg, and 45/15 mg) upon awakening and 8 hours later (twice daily) based on weight if able to swallow tablets. Treatment duration is 24 months.
Drug: Tolvaptan Tablets
Syrup
Tolvaptan (OPC-41061) Tolvaptan tablets will be administered orally as split-dose regimens (15/7.5 mg, 30/15 mg, and 45/15 mg) upon awakening and 8 hours later (twice daily) based on weight if able to swallow tablets.
Number of Participants Reporting Treatment-Emergent Adverse Events (TEAEs)
Number of participants with TEAEs will be assessed from Baseline to post-treatment after 24 months or End of Treatment (EOTx). The EOTx visit applies to participants who discontinue IMP before Month 24. TEAEs are defined as Adverse Events (AEs) with an onset date on or after the start of Investigational Medicinal Product (IMP) treatment. TEAEs are also events continuous from baseline which worsened, became serious, were IMP related, or resulted in death, discontinuation, interruption, or reduction of IMP. An AE is defined as any untoward medical occurrence in a clinical trial subject administered an IMP and which does not necessarily have a causal relationship with this treatment.
Time frame: From baseline to post-treatment after 24 months or EoTx
Annual rate of change of eGFR (by Schwartz formula) from baseline to post-treatment after 24 months
Annual rate of change of eGFR from Baseline to post-treatment after Month 24 or EOTx is calculated using eGFR Schwartz formula = 0.413 × height \[or length, centimeter (cm)\] /serum creatinine milligram per deciliter (mg/dL). The EOTx visit applies to participants who discontinue IMP before Month 24.
Time frame: From Baseline to post-treatment after Month 24 or EOTx
Change from baseline of eGFR (by Schwartz formula) while on treatment at Months 1, 6, 12, 18 and 24 or EOTx
Change from baseline of eGFR is calculated using eGFR Schwartz formula = 0.413 × height \[or length, cm\] /serum creatinine mg/dL) while on treatment at Months 1, 6, 12, 18, and 24 or EoTx. The EOTx visit applies to participants who discontinue IMP before Month 24.
Time frame: At Months 1, 6, 12, 18, and 24 or EOTx
The amount of time between enrollment and 24 months that a subject requires renal replacement therapy (RRT).
To evaluate the effect of tolvaptan on the need for RRT in pediatric participants with ARPKD.
Time frame: From enrollment to 24 months
The percentage of subjects that will receive renal replacement therapy (RRT) by 24 months
Percentage of subjects who receive RRT from baseline through Month 24. RRT is defined as intermittent or continuous hemodialysis, peritoneal dialysis, hemofiltration, hemodiafiltration or kidney transplantation.
Time frame: From Baseline to Month 24
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Plan to share: No
Started Jan 2023 (actual). Primary completion is estimated for Dec 2028, 71 months after the start.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 23, 2026: primary completion Jul 2028 → Dec 2028 and completion Aug 2028 → Dec 2028.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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Studies of the drug tested here: Tolvaptan
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