A Study to Evaluate the Safety and Efficacy of Oral Nizubaglustat (AZ-3102) in Late-infantile and Juvenile Forms of GM1 Gangliosidosis or GM2 Gangliosidosis

Inclusion Criteria: * Confirmed GM1 gangliosidosis or Tay-Sachs, Sandhoff, or GM2AB variant * Male and female participants aged 4 years and older at the time of informed consent * Onset of neurological symptoms from 1 to 10 years * Disability level at Baseline: Ataxic disturbances with a total SARA score of ≥3 and ≤30 at Baseline * Females of childbearing potential who are sexually active willing to follow the contraceptive guidance * Male participants with a female partner of childbearing potential willing to follow the contraceptive guidance Exclusion Criteria: * A history of medical conditions other than GM1 or GM2 gangliosidosis that, in the opinion of the Principal Investigator, would confound scientific rigor or the interpretation of results * Body weight of \<10 kg * The presence of another neurologic disease * The presence of moderate or severe hepatic impairment * The presence of moderate or severe renal impairment * Platelet count of \<100x10\^9/L * The dose of any anti-epileptic treatment(s) was not stable (required a change in dose within the previous 3 months) and/or a new anti-epileptic treatment (drug or procedure) was prescribed in the month before Baseline * Prior use of an investigational drug within the 3 months before Screening; or prior participation in a clinical study involving gene therapy or stem cell transplantation within 2 years prior to Screening * A positive serum pregnancy test (for women of childbearing potential)