Inclusion Criteria:  Adult male and non-pregnant females with classic CAH (simple virilizing or salt-wasting) due to 21-OHD Screening/baseline 17-OHP levels > 5-10 × ULN Is on a daily regimen of glucocorticoid Naïve to prior gene therapy or AAV-mediated therapy  Exclusion Criteria:  Positive for anti-AAV5 antibodies History of adrenalectomy and has no significant liver disease