Intervention periods
Figure Parent Study schema. Inclusion criteria for patient participation in the Extension Study4. Patients are willing to continue to remain without the following prohibited medication from  e) N-acetyl-DL-leucine (e.g., Tanganil®); f) N-acetyl-L-leucine (prohibited if not provided as investigational medicinal product [IMP]); g) Sulfasalazine; h) RosuvastatinFigure Extension Phase schema. Patients will be assessed approximately 4 times over a 64-week period: at the start of the Extension Phase, after 6 months of treatment, 1 year of treatment, and after a 42-day (+ 14 day) post-extension-phase treatment washout