Study of CAD-1883 for Spinocerebellar Ataxia

Key Inclusion Criteria: * Prior Spinocerebellar Ataxia (SCA) diagnosis of the following SCA genotypes: SCA1, 2, 3, 6, 7, 8, 10, 17, or Autosomal Recessive Cerebellar Ataxia Type 1 (ARCA1). * Scale for the Assessment and Rating of Ataxia (SARA) Total score ≥8 and \<30 at Screening * SARA item #1 (gait) score of ≥2 at Screening * Ability to ambulate 8 meters at Screening without assistance from another person Key Exclusion Criteria: * Neurological condition other than SCA that could predominantly explain or contribute significantly to the subjects' symptoms of ataxia or that could confound the assessment of ataxia symptoms (e.g., chronic alcoholism, vitamin deficiencies, multiple sclerosis, Parkinson's disease, Friedreich's ataxia, vascular disease, tumors, paraneoplastic disease, head injury, idiopathic late onset ataxia, multisystem atrophy, stroke, arthritis, cerebral palsy, spasticity of unknown origin). * Moderate or severe scores on the following Inventory of Non-Ataxia Signs (INAS) items at Screening: Dystonia: at least 3 of 5 items; Spasticity: at least 2 of 3 items; Rigidity: at least 2 of 3 items