The purpose of this study is to evaluate long-term Hepatitis B Surface Antigen (HBsAg) seroclearance in participants who completed one of the parent studies (example, REEF-1 [NCT03982186], REEF-2 [NCT04129554], INSIGHT [NCT04585789], REEF-IT [NCT04439539], PENGUIN [NCT04667104]) that included a regimen with JNJ-73763989 for the treatment of chronic Hepatitis B Virus (HBV) infection.

Participants may enroll in Lagoon study after completing one of the parent studies (eg, REEF-1, REEF-2, INSIGHT, REEF-IT, PENGUIN, and other qualifying studies that included a regimen with JNJ-73763989 [JNJ-3989]), which is ribonucleic acid interference (RNAi) for the treatment of chronic HBV infection. In the current study, long-term impact of a combination regimen including JNJ-3989, JNJ-56136379 (JNJ-6379), nucleos(t)ide analogs (NAs) and/or PegIFN, previously administered in 1 of the parent studies, will be assessed. This follow-up study will collect 144-week follow-up data to assess the rate of participants achieving HBsAg seroclearance beyond the follow-up period in the parent studies. During this long-term follow-up (LTFU) study, participants may continue, discontinue or re-start NA treatment as per investigator’s judgement, in line with local treatment guidelines. Assessment like patient-reported outcome(s) (PROs) assessments, electrocardiogram (ECG), vital signs, adverse events, laboratory test results, physical examination will be performed during the study. The duration of the study with long term follow-up is approximately 144 weeks.