Clinical Research Directory

Inclusion Criteria: * Male or female subjects ≥ 4 years and \<18 years of age with a best corrected visual acuity ≤ 1.9 LogMAR (counting fingers) in at least one eye at baseline * Parent/legally authorized representative who have signed and dated informed consent on behalf of the subject; subjects older than 7 years of age may sign and date an assent or give a verbal assent in case of vision loss. * Genetically confirmed diagnosis of syndromic CLN3 disease at screening with EITHER: 1. Two pathogenic/likely pathogenic variants in the CLN3 gene according to the American College of Medical Genetics and Genomics and Association for Molecular Pathology standards and guidelines (Richards et al. 2015), OR 2. One confirmed pathogenic variant AND one variant of unknown significance, PLUS secondary confirmation with evidence of characteristic inclusions on electron microscopy, or vacuolated lymphocytes as an alternative AND a characteristic clinical course suggestive of CLN3 syndromic disease according to the age. There is no restriction on the specific CLN3 mutations for eligibility to enroll in the study. The mutations will be recorded in the electronic case report form (eCRF) for potential use in determining if CLN3 genotype is associated with tolerability or efficacy of Batten-1 therapy. * Male and female subjects of child-bearing potential that are sexually active must use a highly effective method of contraception with a Pearl-Index \< 1 % and must continue for the duration of the trial (and for 30 days after the end of treatment). * Can complete study assessments (subject \[e.g., absence of cataracts at baseline that preclude visual acuity assessment\] and/or caregiver \[compliance to study procedures\]) and return to the clinic as scheduled. Exclusion Criteria: * Subjects with non-syndromic variants reported to be associated with a vision-only phenotype or subjects above 8 years with clinical presentation at baseline of vision-only phenotype. * Have been evaluated at baseline visit with a LogMAR score \> 1.9 for best corrected visual acuity. * Have any ocular conditions that in the opinion of the investigator might affect visual assessments (e.g. cataract, glaucoma, diabetes, amblyopia, etc…). * Have received gene therapy or stem cell therapy intended to modify the course of CLN3 disease. * Have participated in another interventional study during the last three months before screening. * Have been exposed to miglustat within 1 week prior to baseline, or is scheduled to receive an investigational device or drug (other than test product) during the study. * Have a medical condition that, in the opinion of the investigator, would interfere with the efficacy or safety assessments or increase the subject's risk of adverse events (AEs), including any active malignancy of any type except non-melanoma skin cancer. * Have a clinically significant abnormality in their clinical laboratory values (hematology, chemistry) at screening that would preclude their participation in the study. * Have a cardiac impairment including repolarization disturbances (prolonged QTc), ventricular hypertrophy and sinus node dysfunction with severe bradycardia and other conduction issues. * Have a known allergy or hypersensitivity to miglustat, or any component of the Investigational Medicinal Product (IMP) formulation. * Have a severe renal disease (estimated Glomerular Filtration Rate (eGFR) \< 30 mL/min). * Have a medical history of HIV, hepatitis B, hepatitis C, or positive results at screening.