A 2 PART STUDY EVALUATING EDP-721 IN HEALTHY SUBJECTS AND EDP-721 IN COMBINATION WITH EDP-514 IN PATIENTS WITH CHRONIC HEPATITIS B VIRUS INFECTION.

Part 1 (HV Population): Inclusion Criteria: * 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 65 years, inclusive. 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. * Receipt of any vaccine, an investigational agent or biological product within 28 days or 5 times the t½, whichever one is longer, prior to first dose. Part 2 (CHB Population) Inclusion Criteria (Nuc-Suppressed CHB Population) * 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 70 years, inclusive * HBsAg detectable in serum/plasma at Screening and in the most recent HBsAg serum/plasma testing at least 6 months previously. * HBV DNA levels: * A Screening HBV DNA level in serum/plasma that is \<LLOQ and * No HBV DNA serum/plasma test values ≥LLOQ over the previous 12 months (using an approved test) * CHB subjects must have been on their prescribed HBV NUC treatment with no change in regimen for 12 months prior to Screening Inclusion Criteria (Viremic CHB Population): * 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 70 years, inclusive * HBsAg detectable in serum/plasma at Screening and in the most recent HBsAg serum/plasma testing at least 6 months previously. * HBV DNA levels: * For subjects who are HBeAg positive at Screening, a Screening HBV DNA level in serum/plasma that is ≥20,000 IU/ml, or * For subjects who are HBeAg negative at Screening, a Screening HBV DNA level in serum/plasma that is ≥2,000 IU/mL, and * For all subjects, no HBV DNA serum/plasma test values \<1,000 IU/ml over the previous 12 months (using an approved test) * CHB subjects must not have been on prescribed anti-HBV treatment, specifically pegIFN and/or NUC therapy for at least 12 months prior to Screening Exclusion Criteria (Nuc-Suppressed and Viremic CHB Population): * A documented prior diagnosis of cirrhosis * Pregnant or nursing females * Coinfection with human immunodeficiency virus (HIV), HCV, HDV, HAV, or HEV * Chronic liver disease of a non-HBV etiology; coexisting liver or biliary diseases