Inclusion Criteria: 

• Male or female adult with Autosomal Dominant Polycystic Kidney Disease (ADPKD) with age at the time the consent is signed:
  • between 18 to 50 years (both inclusive) for patients from Stage 1;
  • between 18 to 50 years (both inclusive) for patients from Stage 2 with eGFR between 45 and 89.9 mL/min/1.73 m^2 during screening period*;
  • between 18 to 55 years (both inclusive) for patients from Stage 2 with eGFR between 30 and 44.9 mL/min/1.73 m^2 during screening period*.
• Diagnosis of AKPKD in patients with a family history will be based on unified Pei criteria. In the absence of a family history, the diagnosis will be based on the presence of renal cysts bilaterally, totaling at least 20, in the absence of findings suggestive of other cystic renal diseases.
• Mayo Imaging Classification of ADPKD Class 1C, 1D or 1E**
  • **Total kidney volume (TKV) must be confirmed by a central reader prior to Visit 3.
• Estimated glomerular filtration rate between 45 to 89.9 mL/min/1.73 m^2 during screening period* (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) for Stage 1.
• Estimated glomerular filtration rate between 30 to 89.9 mL/min/1.73 m^2 during screening period* (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) for Stage 2.
• *Eligibility will be confirmed by eGFR value from one of the two first pre-randomization eGFR measurements.
• Stable treatment regimen of antihypertensive therapy for at least 30 days prior to the screening visit for hypertensive patient.
• Able to read, comprehend, and respond to the study questionnaires.
• Patient has given voluntary written informed consent before performance of any study related procedures not part of standard medical care.
• Patient does not have access to tolvaptan at the time of study start or tolvaptan is not indicated for treatment of patient according to treating physician (patient does not meet recommended criteria for treatment, refuses to initiate or does not tolerate treatment with tolvaptan).
• The patient, if female of childbearing potential, must have a negative blood pregnancy test (β-human chorionic gonadotropin [β-hCG]) at the screening visit and a negative urine pregnancy test at the baseline visit.
• Female patients of childbearing potential and male patients must agree to practice true abstinence in line with their preferred and usual lifestyle or to use double-contraceptive methods (including a highly effective method of contraception for female participants of childbearing potential) for the entire duration of the study and for at least 6 weeks for females and 90 days for males following their last dose of study drug.

Exclusion Criteria:

• Systolic BP > 160 mmHg* at run-in and baseline visits.
• *mean value of three or five systolic BP measurements.
• Administration within 3 months prior to the screening visit of tolvaptan or other Polycystic Kidney Disease-modifying agents (somatostatin analogues).
• The patient, in the opinion of the Investigator, is unable to adhere to the requirements of the study or unable to undergo study assessments; e.g., has contraindications to pupillary dilation or unable to undergo magnetic resonance imaging [MRI]) [For example: patient’s weight exceeds weight capacity of the MRI, ferromagnetic metal prostheses, aneurysm clips, severe claustrophobia, large abdominal/back tattoos]).
• The patient has, according to World Health Organization (WHO) Grading, a cortical cataract ≥1-quarter of the lens circumference (Grade cortical cataract-2 [COR-2]) or a posterior subcapsular cataract ≥ 2 mm (Grade posterior subcapsular cataract-2 [PSC-2]). Patients with nuclear cataracts will not be excluded.
• The patient is currently receiving potentially cataractogenic medications, including a chronic regimen (more frequently than every 2 weeks) of any route of corticosteroids (including medium and high potency topical steroids), or any medication that may cause cataract, according to the Prescribing Information.
• The patient has received strong or moderate inducers or inhibitors of CYP3A4 within 14 days or 5 half-lives, whichever is longer, prior to randomization. This also includes the consumption of grapefruit, grapefruit juice, or grapefruit containing products within 72 hours of starting venglustat administration.