The goals of therapy against chronic hepatitis B are to decrease the morbidity and mortality related to chronic HBV infection. Currently available antiviral therapy can suppress viral replication but only a small proportion attain functional cure, which is defined as HBV surface antigen-to-antibody seroconversion. Hepatitis B surface antigen (HBsAg) is a marker of persistent hepatitis B infection.

It has been observed that patients who had both hepatitis B and hepatitis C, and who were treated for their hepatitis C with 12 weeks of ledipasvir/sofosbuvir for had a decline in HBsAg levels. This study hypothesizes that a similar decrease would be seen in mono-infected hepatitis B subjects over the course of 12 weeks treatment with ledipasvir/sofosbuvir.

INCLUSION CRITERIA

Participants in Groups A, C & D (Chronic HBV, low replicative state not requiring treatment):

1. Provision of signed and dated informed consent form

2. Stated willingness to comply with all study procedures and availability for the duration of the study

3. Male or female, aged 18 or older at screening

4. Diagnosed with chronic hepatitis B infection defined as one of the following:

   1. HBsAg or HBV DNA positivity for at least 6 months
   2. Medical records indicating a chronic HBV infection

5. HBeAg negative at screening

6. HBV DNA > lower level of quantitation (LLOQ)

7. Quantitative HBsAg at least 10 IU/mL at screening

8. Ability to take oral medication and be willing to adhere to the twelve week study drug regimen

9. For females of reproductive potential: usual practice of complete abstinence from sexual intercourse with a member of the opposite sex OR use of at least one form of highly effective contraception for at least 1 month prior to enrollment and agreement to use such a method during study participation and for an additional 30 days after the end of study drug administration

10. For males of reproductive potential: usual practice of complete abstinence from sexual intercourse with a member of the opposite sex OR use of at least one form of highly effective contraception for at least 1 month prior to enrollment and agreement to use such a method during study participation and for an additional 14 days after the end of study drug administration

11. Ability to communicate effectively with the study investigator and key staff

12. Medical management provided by a primary care provider

13. Ability to store medications at a room temperature of less than 86 degrees Fahrenheit

14. Not on antiviral therapy or requiring treatment for HBV during screening

Participants in Group B (Chronic HBV, virally suppressed):

1. Provision of signed and dated informed consent form

2. Stated willingness to comply with all study procedures and availability for the duration of the study

3. Male or female, aged 18 or older at screening

4. Diagnosed with chronic hepatitis B infection defined as one of the following:

   1. HBsAg or HBV DNA positivity for at least 6 months
   2. Medical records indicating a chronic HBV infection

5. Receiving oral anti-HBV medications (either tenofovir alafenamide, tenofovir disoproxil fumarate, entecavir, or a combination of no more than 2 of these agents) for at least three months prior to enrollment

6. HBV DNA ˂ lower level of quantitation (LLOQ) at screening and for at least three months prior

7. Quantitative HBsAg at least 10 IU/mL at screening

8. Ability to take oral medication and be willing to adhere to the twelve week study drug regimen

9. For females of reproductive potential: usual practice of complete abstinence from sexual intercourse with a member of the opposite sex OR use of at least one form of highly effective contraception for at least 1 month prior to enrollment and agreement to use such a method during study participation and for an additional 30 days after the end of study drug administration

10. For males of reproductive potential: usual practice of complete abstinence from sexual intercourse with a member of the opposite sex OR use of at least one form of highly effective contraception for at least 1 month prior to enrollment and agreement to use such a method during study participation and for an additional 14 days after the end of study drug administration

11. Ability to communicate effectively with the study investigator and key staff

12. Medical management provided by a primary care provider

13. Ability to store medications at a room temperature of less than 86 degrees Fahrenheit

EXCLUSION CRITERIA

1. Coinfection with hepatitis C, hepatitis D or human immunodeficiency virus (HIV)

2. Pregnancy or lactation

3. Known allergic reactions to sofosbuvir or ledipasvir

4. Treatment with another investigational drug or other intervention within three months

5. Evidence of cirrhosis or hepatic decompensation such as:

   • Platelets less than 100,000 /mm3
   • Albumin less than 3.5 g/dL
   • INR greater than 1.7 or Prothrombin time of 1.5 times the upper limit of normal (ULN)
   • Total bilirubin of 1.5 times the upper limit of normal
   • FibroTest (or FibroSure®) of 0.75 or greater

6. Abnormal hematological and biochemical parameters at screening including:

   • White blood cell count less than 2500 cells/uL
   • Absolute neutrophil count (ANC) less than 1,000 cells/mm3 (less than 750 mm3 for African or African-American subjects)
   • Hemoglobin less than 12 g/dL for males, less than 11 g/dL for females
   • AST or ALT of two times the upper limit of normal
   • Estimated GFR less than 50 mL/min
   • Glycosylated hemoglobin (HbA1c) greater than 8.5%

7. Current or prior history of any of the following:

   • Immunodeficiency disorders or autoimmune disease (e.g. Systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel diseases, sarcoidosis, psoriasis of greater than mild severity)
   • Severe pulmonary disorders, significant cardiac diseases
   • Gastrointestinal disorder with post-operative condition that could interfere with the absorption of the study drugs
   • Significant psychiatric illness that in the judgment of the Investigator, is a contraindication to protocol participation or impairs a volunteer's ability to give informed consent
   • Any malignancy diagnosed within 5 years (not including recent localized treatment of squamous or non-invasive basal cell skin cancer; cervical carcinoma in situ appropriately treated prior to screening)
   • Solid organ transplantation
   • Poor venous access

8. Screening ECG with clinically significant findings

9. Evidence of HCC (e.g., α fetoprotein > 50ng/mL or radiologic evidence)

10. Clinically significant illicit drug or alcohol abuse within 12 months of screening. Subjects on methadone maintenance treatment or prescribed opioid may be included.

11. Use of amiodarone within 90 days of enrollment; or carbamazepine, phenytoin, phenobarbital, oxcarbazepine, rifabutin, rifampin, rifapentine, St. John's wort, rosuvastatin, or interferon within 30 days of enrollment or expected use of these prohibited drugs during study participation. Use of or expected need of proton-pump inhibitors more than 20 mg omeprazole equivalent or H2 receptor antagonist more than 40 mg famotidine BID equivalent within 7 days of enrollment.

24 weeks

Ten potential subjects for Groups C and D will be randomized in a 1:1 fashion.