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.

A Phase 1a/1b Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Single and Multiple Ascending Doses of EDP-721 in Healthy Subjects (Part 1) and the Safety, Tolerability, Pharmacokinetics, and Antiviral Activity of EDP-721 in Combination With EDP-514 in Patients With Chronic Hepatitis B Virus Infection (Part 2)

Part 1 is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability, and pharmacokinetics of single and multiple ascending doses of EDP-721 in healthy subjects.

Part 2 is a randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability, pharmacokinetics and antiviral activity of 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