An Exploratory, Randomized, Double-blind, Placebo-controlled, Multicenter Study to Evaluate the Efficacy, Safety, Tolerability and Pharmacokinetics of Orally Administered GLPG2737 for 52 Weeks, Followed by an Open-label Extension Period of 52 Weeks in Participants With Autosomal Dominant Polycystic Kidney Disease

DB Period: Mean Percent Change From MRI Baseline in htTKV

Time Frame: MRI Baseline up to Week 52

htTKV is used in participants with ADPKD disease to predict the onset of renal insufficiency. htTKV was calculated using TKV (in mL) obtained from MRI divided by height (in m). MRI Baseline: For MRI assessments, all non-missing values before the first study drug administration in the study +14 days (included) was considered as the primary baseline definition. Results were derived by mean of the individual slopes (i.e. using all MRI performed between baseline and Week 52).

DB Period: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious TEAEs

Time Frame: From first dose to Week 56

An AE is any untoward medical occurrence in a participant administered a study drug, and which does not necessarily have to have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of the study drug, whether or not considered related to it. A serious adverse event (SAE) is defined as any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, results a congenital anomaly/birth defect or other medically important event. A TEAE was defined as an AE observed after starting administration of the study drug until 30 days after last DB dose or 1 day before OLE dose, whichever occurred first.