JNJ-73763989 is a liver-targeted antiviral therapeutic for subcutaneous injection designed to treat chronic hepatitis B virus (HBV) infection via ribonucleic acid interference mechanism. This phase 2 study is designed to evaluate safety and efficacy of JNJ-73763989 in HBV infected patients who are co-infected with HDV. The study consists of 2 parts: Part 1 will evaluate safety, tolerability and antiviral activity of JNJ-73763989 + NA while Part 2 will evaluate the safety and efficacy of the JNJ-73763989 + NA regimen in the treatment of HBV/HDV co-infection. Each part includes 3 phases: Screening phase (from 4 Week up to maximum of 8 weeks), Intervention phase (144 Week for Arm A and 148 Week for Arm B) and Follow-up phase (48 Week). The duration of individual study participation will be between 196 and 204 weeks. Safety and tolerability (including adverse events [AEs] and Serious AEs, laboratory assessments, electrocardiogram [ECG], vital signs, physical examination), efficacy (including HDV ribonucleic acid [RNA], HBV deoxyribonucleic acid [DNA] and antigens) , and pharmacokinetics will be assessed throughout the study.
The purpose of the study is to evaluate on-treatment efficacy against hepatitis D virus (HDV) of JNJ-73763989 + nucleos(t)ide analog (NA) regimen compared to NA alone.