A Study of EDP 305 in Healthy Subjects and Subjects With Presumptive NAFLD

Inclusion Criteria for all SAD and MAD Subjects:: * An informed consent document signed and dated by the subject. * Healthy male and female subjects of any ethnic origin between the ages of 18 and 55 years, inclusive. * Female subjects must be of non-childbearing potential. * All male participants who have not had a vasectomy must use effective contraception from Day -1 to 90 days after their last dose of study drug. * For healthy volunteers only (see below for Subjects with presumptive NAFLD): Body mass index of 18 to 30 kg/m2 with a minimum body weight of 50 kg. Additional Inclusion Criteria for MAD Subjects with Presumptive NAFLD: * Body mass index of \>28 and \<35 kg/m2 at screening. WITH or WITHOUT one of the following: * Type 2 diabetes mellitus diagnosed by one of the following methods: * As defined by the American Diabetes Association (ADA), as one of the following criteria: a) symptoms of diabetes plus casual plasma glucose concentration \>200 mg/dL (11.1 mmol/L) OR b) Fasting plasma glucose \>126 mg/dL (7.0 mmol/L) OR c) 2-hour post-load glucose \>200 mg/dL (11.1 mmol/L) during a 75 g oGTT. * HbA1c of at least 6.5%. --- OR--- * Prediabetes diagnosed as defined by the ADA as a) an HbA1c of 5.7% - 6.4% OR b) fasting blood glucose of 100-125 mg/dL OR c) an oGTT 2-hour blood glucose of 140 mg/dL - 199 mg/dL. Exclusion Criteria: * Clinically relevant evidence or history of illness or disease. * Pregnant or nursing females. * History of febrile illness within 7 days prior to the first dose of study drug or subjects with evidence of active infection. * A positive urine drug screen at screening or Day -1. * Current tobacco smokers or use of tobacco within 3 months prior to screening. * Any condition possibly affecting drug absorption (e.g., gastrectomy, cholecystectomy). * History of regular alcohol consumption * Participation in a clinical trial within 30 days prior to study drug administration. * Use of prescription drugs, non-prescription drugs, dietary supplements including Vitamin E herbal supplements, hormonal therapy/replacement or CYP3A4 substrates, inducers and inhibitors within 14 days prior to the first dose of study medication. Additional Exclusion Criteria for MAD Subjects with Presumptive NAFLD: * Subjects taking any antidiabetic medication. * Subjects with unstable proliferative retinopathy, macular oedema (fundus examination performed in the previous year will be considered relevant on Investigator's judgement). * Subject has taken fibrates, statins, and/or Vitamin E within 6 weeks prior to the first dose administration. * Subjects with a history of bariatric surgery and any other gastrointestinal surgery relative to weight loss. * Subjects with common causes of secondary hepatic steatosis.