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

This is a multicenter, open-label, randomised, phase II study. The study will be conducted in Russia and Germany. The study is designed to evaluate the benefit of 3 MXB doses versus observation in patients on background therapy with tenofovir, suffering from hepatitis delta with very limited therapeutic options; the patients will be randomized 1:1:1:1 into 3 treatment arms and an observation arm. Patients with compensated cirrhosis at screening will be stratified to allow similar distribution into each treatment arm. If patients were not receiving treatment with nucleoside/nucelotide analogue, the comparator/background drug will be initiated after the eligibility confirmation, for 12 weeks prior to randomization visit; patients who previously received tenofovir will continue the dosing; patients on different nucleoside/nucleotide analogue will be switched to tenofovir. Observation is considered an adequate control group, as daily placebo injections for 24 weeks are regarded not feasible and ethically questionable. It is planned to screen 200 patients, and 120 patients will be randomised into four treatment arms in the 1:1:1:1 ratio. * Arm A (30 patients): Myrcludex B, 2 mg/day subcutaneously (s.c.) for 24 weeks + tenofovir with a further follow-up period of 24 weeks of continued tenofovir therapy. * Arm B (30 patients): Myrcludex B, 5 mg/day subcutaneously (s.c.) for 24 weeks + tenofovir with a further follow-up period of 24 weeks of continued tenofovir therapy. * Arm C (30 patients): Myrcludex B, 10 mg/day subcutaneously (s.c.) for 24 weeks + tenofovir with a further follow-up period of 24 weeks of continued tenofovir therapy. * Arm D (30 patients): tenofovir treatment for 48 weeks.