Proof-of-concept Study Evaluating the Safety and Efficacy of EBP921 in Delta Hepatitis (HDV)

Inclusion Criteria: 1. Men and women age 18 or older with the capacity to give written informed consent 2. Patients with compensated chronic HDV infection as indicated by presence of anti-HDV in serum. 3. Liver biopsy should be performed within one-year of study screening and graded using the Knodell scoring system. 4. Presence of HDV antigen in liver tissue or HDV-RNA in serum. 5. Active HBV replication will not exclude patients. 6. Previous therapy with standard alpha-interferon or peginterferon will not exclude patients. 7. Patients who are HBV therapy-naïve or who previously received HBV antiviral therapy will be eligible. Patients currently taking HBV antiviral therapy will e considered on a case basis. 8. Female subjects of reproductive potential and female partners of male subjects should be on two reliable forms of contraception from the start of the study until 60 days from the end of EBP921 dosing. Exclusion Criteria: 1. Severe neuropsychiatric disorders 2. History or clinical manifestations of significant metabolic, hematological, pulmonary, ischemic heart disease, significant or unstable heart disease, gastrointestinal, neurological, renal, urological, endocrine, ophthalmologic disorders including severe retinopathy, or immune-mediated disease 3. Pregnant or breast-feeding patients or the inability to practice adequate contraception during the conduct of the study 4. Underlying autoimmune/immune-deficiency disease (e.g., lupus, sarcoidosis, celiac disease, HIV antibody positive, AIDS) 5. Chronic (\> 4 weeks duration) diarrhea 6. Body weight \> 128 kg and \< 40 kg 7. Uncompensated cirrhosis 8. Absolute neutrophil count less than 1500 per cubic millimeter 9. Platelet count less than 90,000 per cubic millimeter 10. Evidence of concurrent HCV infection with positive serum HCVRNA 11. Evidence of hepatocellular carcinoma 12. Active substance abuse (alcohol, inhaled or injected drugs) within the past 12 months 13. Diagnosis of malignancy in the previous five years excluding superficial dermatologic malignancies 14. Any experimental therapy in the previous 6 months prior to enrollment. 16\. Patients with a history of multiple drug resistant HBV 17. Patients receiving interferon therapy for any reason.