Therapeutic Exploratory Phase 2 Study to Evaluate the Safety and Efficacy of MB12066 in Patients With Nonalcoholic Fatty Liver Disease(NAFLD) Except Cirrhosis

Inclusion Criteria: * NAFLD Activity Score(NAS) ≥ 3 (Biopsy-proven) Exclusion Criteria: * Alcohol consumption \> 20g/day * Type 1 diabetes or poorly controlled diabetes mellitus (HbA1c ≥ 9%) * Evidence of other chronic liver disease (e.g. HBsAg positive, anti-HCV positive, autoimmune hepatitis, Wilson's disease, alpha-1 antitrypsin deficiency and etc.) * ALT, AST \> 5X the upper limit of normal * Serum creatinine ≥ 2mg/dl * Fibrosis score ≥ 3 according to the NASH CRN fibrosis staging system * NQO1 T/T type * Weight loss of more than 5kg within 6 months * Bariatric surgery within 6 months * Known alcohol or any other drug abuse in the last five years * Insulin sensitizers, hepatoprotective agents, anti-oxidants, lipid-lowering agents, drugs induced fatty liver within 1 month