Study Evaluating Patients With Cystinuria and Efficacy and Safety Exploratory Study in the Youngest Children

Inclusion Criteria: * 1\. Patient who has a diagnosis of cystinuria based on medical diagnosis (at least one previous orcurrent episode of calculus of cystine, and/or one previous or current episode of cystine crystalluria) or on genetic diagnosis (only for patients enrolled in B13CS study). 2\. Patient treated with an alkalising treatment at a well-adapted dose (defined as a daily dose deemed by the investigator aiming to maintain overtime urinary pH value ≥ 7.0 and/or compatible with an acceptable safety profile and/or patient's constraints or compliance). 3\. Patient who, when treated with a second line therapy (chelator agent), presents a disease status enabling interruption of the chelator agent during the course of the B12CS-B13CS research. 4\. Patient male or female, including child aged between 6 months and 17 years old and adult aged ≥ 18 years old up to 70 years old. 5\. For female patient of childbearing potential (defined by CTFG as fertile, following menarche until becoming post-menopausal unless permanently sterile\*) a highly effective birth control method should be used until the end of study plus 36 hours after the last dose of IMP. 6\. Patient and/or parents or legal representative(s) who is(are) willing and able to participate in the study, to understand and to comply with study procedures for the entire length of the study. 7\. Patient or parents or legal representative(s) who has/have provided a signed written informed consent. 8\. P…