B-Ensure: 베피로버센 임상시험 참여자에서 치료 반응의 지속성 평가 장기 추적 연구

This multi-country, longitudinal follow-up study will enrol adults with chronic hepatitis B (CHB) who previously participated in the Phase III B-Well-1 ((202009: NCT05630807) or B-Well-2 (219288: NCT05630820) studies, received 24 weeks of Bepirovirsen treatment, and achieved hepatitis B surface antigen (HBsAg) levels less than or equal to (\<=) 100 International units per millilitres (IU/mL) at Week 72 without achieving functional cure. No investigational treatment will be administered in this study. Participants will be followed approximately every 6 months for up to 4 years, and retrospective data will be collected from Week 72 of the parent study until enrolment. The study aims to evaluate the long-term durability of HBsAg suppression and disease-related outcomes. The study will end at the last visit of the last participant globally (Month 48). The primary objective of the study is to describe the long-term durability of HBsAg reduction in participants who achieved HBsAg levels ≤100 IU/mL at Week 72 following 24 weeks of Bepirovirsen treatment.