Long-term Treatment of Autosomal Dominant Polycystic Kidney Disease (ADPKD) With Venglustat

Inclusion criteria :

- Male or female adult with ADPKD who had completed the treatment period in Stage 1 or
Stage 2 of Study EFC15392 (NCT03523728).

- The participants who had an eGFR >30 mL/min/1.73 m^2:

1. Measured at Visit 11 of the EFC15392 study for participant enrolled in the
LTS15823 study at the time of Visit 12 (Month 24; end-of treatment visit) of the
EFC15392 study.

2. Measured at Screening visit for participant enrolled in the LTS15823 study not
concomitantly to the Visit 12 (Month 24; end-of treatment visit) of the EFC15392
study.

- Contraceptive used by men and women should be consistent with local regulations
regarding the methods of contraception for those participating in clinical studies.

1. Male participants who agreed to practice true abstinence in line with their
preferred and usual lifestyle or to use double-contraceptive methods for the
entire duration of the study and for at least 90 days following their last dose
of IMP.

2. Female participants who had a negative urine pregnancy test at the Baseline visit
and agreed 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 the entire duration of the study and for at least 6
weeks following their last dose of IMP.

- Capable of giving signed informed consent before performance of any study related
procedures not part of standard medical care.

- Able to read, comprehend, and respond to the study questionnaires.

Exclusion criteria:

- For participants who had lag phase between the end of the EFC15392 study and Screening
visit (Visit 0) in the LTS15823 study.

- The participant had a new clinically significant, uncontrolled medical condition that,
in the opinion of the Investigator, would put the safety of the participant at risk
through participation, or which would affect the efficacy or safety analysis if the
condition exacerbated during the study, or that might significantly interfere with
study compliance, including all prescribed evaluations and follow-up activities.

- A history of drug abuse and/or alcohol abuse or alcohol dependence during the lag
phase between the end of the EFC15392 study and Screening visit (Visit 0) in the
LTS15823 study when applicable.

- Administration of tolvaptan or other polycystic kidney disease-modifying agents
(somatostatin analogues) within 3 months prior to the Screening visit (Visit 0) in the
LTS15823 study when applicable.

- The participant was 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 participant had received strong or moderate inducers or inhibitors of CYP3A4
within 14 days or 5 half lives, whichever was longer, prior to the Baseline visit
(including consumption of grapefruit-containing products within 72 hours of starting
venglustat administration).

- Participation in another investigational interventional study or use of IMP, within 3
months or 5 half-lives, whichever was longer, before the Baseline visit (Visit 1)
except participation in the EFC15392 study when applicable.

- Liver enzymes (alanine aminotransferase /aspartate aminotransferase) or total
bilirubin >2 times the upper limit of normal unless the participant had the diagnosis
of Gilbert syndrome. Participants with the Gilbert syndrome should had no additional
symptoms or signs which suggest hepatobiliary disease and serum total bilirubin level
no more than 3 milligrams per decilitre (mg/dL) (51 micromoles per litre [μmol/L])
with conjugated bilirubin less than 20 percent (%) of the total bilirubin fraction.

For participants with or without lag phase between the end of EFC15392 study and entry into
LTS15823 study:

- The participant was pregnant or lactating.

- Presence of severe depression as measured by BDI-II >28 at Visit 1 (for participants
enrolled in the LTS15823 study at the time of the end of treatment visit of the
EFC15392 study) or at Visit 0 (for participants enrolled in the LTS15823 study after
the end-of-treatment visit of the EFC15392 study).

- Sensitivity to any of the study interventions, or components thereof, or drug or other
allergy that, in the opinion of the Investigator, contraindicates participation in the
study.

The above information was not intended to contain all considerations relevant to a
participant's potential participation in a clinical trial.