A Multicenter, Open-label, Randomized Clinical Study to Assess Efficacy and Safety of 3 Doses of Myrcludex B for 24 Weeks in Combination With Tenofovir Compared to Tenofovir Alone to Suppress HBV Replication in Patients With Chronic Hepatitis D

Inclusion Criteria: 1. Age from 18 to 65 years inclusively at the time of signing Informed Consent Form. 2. Positive serum HBsAg for at least 6 months before Screening. 3. Positive serum anti-HDV antibody for at least 6 months before screening. 4. Positive PCR results for serum HDV RNA at Screening. 5. Patients with liver cirrhosis, irrespective of previous interferon treatment . 6. Patients without liver cirrhosis, who failed prior interferon treatment or for whom, in the opinion of the Investigator, such treatment is currently contraindicated (including history of interferon intolerance) . 7. Alanine aminotransferase level \>1 x ULN, but less than 10 x ULN. 8. Previous nucleotide/nucleoside analogue treatment within at least 12 weeks prior to the planned start of study treatment or subject's willingness to take tenofovir for at least 12 weeks prior to the planned start of study treatment. 9. Negative urine pregnancy test for females of childbearing potential. 10. Inclusion criteria for female subjects: * Postmenopausal for at least 2 years, or * Surgically sterile (total hysterectomy or bilateral oophorectomy, bilateral tubal ligation, staples, or another type of sterilization), or * Abstinence from heterosexual intercourse throughout the study, or * Willingness to use highly effective contraception throughout the study and for 3 months after the last dose of the study medication. 11. Male and female subjects must agree to use a highly effective contraception throughout the study and for 3 months after the last dose of the study medication. 12. Male subjects must agree not to donate sperm throughout the study and for 3 months after the last dose of the study medication. Exclusion Criteria: 1. Child-Pugh score of B-C or over 6 points. 2. HCV or HIV coinfection. Subjects with anti-HCV antibodies can be enrolled, if screening HCV RNA test is negative. 3. Creatinine clearance \<60 mL/min. 4. Total bilirubin ≥ 2mg/dL. Patients with higher total bilirubin values may be included after the consultation with the Study's Medical Monitor, if such elevation can be clearly attributed to Gilbert's syndrome associated with low-grade hyperbilirubinemia. 5. Any previous or current malignant neoplasms, including hepatic carcinoma.