Inclusion Criteria: * Male or female, age at least 6 years at the time of signing the informed consent (and assent, if applicable). * Diagnosis of FA, based on clinical phenotype and genotype (GAA expansion on the frataxin gene) * Onset of FA on or before 25 years of age * Confirmed left ventricular hypertrophy and abnormal left ventricular mass index * Left ventricular ejection fraction at least 30% * Anti-AAVrh.10 total antibody titer less than the protocol-specified maximum level Exclusion Criteria: * Presence of other forms of cardiomyopathy that contribute to heart failure * Current use of inotrope infusion or presence of a ventricular assist device * Contraindication to cardiac MRI * Prior organ transplant * Previous gene transfer or cell therapy * Poorly controlled diabetes (hemoglobin A1c ≥8%) * Active hematologic or solid organ cancer Other inclusion/exclusion criteria to be applied as per protocol.