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 18 months over the course of the study.~The overall trial duration is expected to be approximately 3.5 years.
The primary objective of this study is to evaluate the safety of tolvaptan in pediatric subjects with autosomal recessive polycystic kidney disease (ARPKD)