> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/long-term-follow-up-study-to-evaluate-durability-of-9f9f89f7-30c1-471a-b2b6-19c9787eb0d1 > Record changed: 2026-10-13 # Long-term Follow-up Study to Evaluate Durability of Treatment Response in Previous Bepirovirsen Study Participants (B-Sure) NCT04954859 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) Phase Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) Recruitment status Active, not recruiting Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) Participants 360 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) Lead sponsor GlaxoSmithKline Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) Start date 2021-12-14 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) Number of sites 163 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) ## Title and summary **Summary** This is a global multi-center, long-term follow-up study to assess durability of efficacy, as measured by maintenance of treatment response from the parent study, in participants who participated in a previous bepirovirsen study and achieved a complete or partial response. Eligible participants will be enrolled in this study after completing the end of study (EoS) visit in the respective parent bepirovirsen studies (studies B-Clear \\\[209668: NCT04449029\\\], B-Together \\\[209348: NCT04676724\\\], B-Fine \\\[212602: NCT04544956\\\], B-Well 1 \\\[202009: NCT05630807\\\], B-Well 2 \\\[219288: NCT05630820\\\], and TH HBV ASO-001 \\\[217023: NCT05276297\\\]). Participants will be categorized as Not-on-NA, NA-cessated, or On-NA based on their nucleos(t)ide analogue (NA) status in the parent study. No further treatment with bepirovirsen will be administered in this study. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Acronym** B-Sure Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Short title** Long-term Follow-up Study to Evaluate Durability of Treatment Response in Previous Bepirovirsen Study Participants (B-Sure) Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Official title** A Prospective, Multi-Centre Study (B-Sure) to Evaluate Long-Term Durability of Treatment Response in Chronic Hepatitis B Participants With and Without Nucleos(t)Ide Therapy Who Have Participated in a Previous Bepirovirsen Treatment Study Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) ## Status and phase **Control arm** Open label Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Recruitment status** Active, not recruiting Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Phase** Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) ## Dates **Completion date** 2029-01-24 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **First posted** 2021-07-08 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Registry last updated** 2026-06-24 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Primary completion date** 2029-01-24 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Start date** 2021-12-14 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) ## Size and sites **Participants** 360 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Participant count basis** Estimated Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Planned participants** 360 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Protocol amendments** 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Number of sites** 163 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) ## Sponsor and oversight **Data monitoring committee** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Lead sponsor** GlaxoSmithKline Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) ## Identifiers **Registry ID** NCT04954859 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **ClinicalTrials.gov ID** NCT04954859 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) ## Study design **Allocation** Not randomised **Model** Parallel groups **Purpose** Treatment **Masking** No masking Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) ## Outcomes ### Primary outcomes 1. Percentage of Not-on-NA participants without loss of parent study primary outcome (PSPO) Timeframe: From primary endpoint assessment in the parent study up to Month 57 NA indicates nucleos(t)ide analogue (NA). 2. Percentage of On-NA participants rolling over from studies 209668 and 209348 without loss of functional cure (FC) after NA-cessation in study 206882 Timeframe: From Month 3 up to Month 57 3. Percentage of On-NA participants rolling over from study 217023 without loss of FC after NA-cessation in study 206882 Timeframe: From Month 3 up to Month 33 4. Percentage of NA-cessated participants rolling over from studies 202009 and 219288 without loss of FC after NA-cessation in the parent study Timeframe: From primary endpoint assessment in the parent study up to Month 33 ### Secondary outcomes 1. Percentage of On-NA and NA-cessated participants with PSPO in the parent study who have hepatitis B surface antigen (HBsAg) reversion or use of any rescue medication after NA cessation (in either parent study or study 206682) Timeframe: Up to Month 57 2. Percentage of On-NA and NA-cessated participants with PSPO in the parent study who have virologic relapse or use of any rescue medication after NA cessation (in either parent study or study 206682) Timeframe: Up to Month 57 3. Percentage of On-NA and NA-cessated participants with PSPO in the parent study who have clinical relapse or use of any rescue medication after NA cessation (in either parent study or study 206682) Timeframe: Up to Month 57 4. Percentage of On-NA and NA-cessated participants with PSPO in the parent study who receive NA retreatment after NA cessation (in either parent study or study 206682) Timeframe: Up to Month 57 5. Percentage of On-NA participants with PSPO in the parent study, who continue NA treatment in study 206882, and have no loss of treatment response Timeframe: From primary endpoint assessment in the parent study up to Month 33 6. Percentage of Not-on-NA participants with a partial response in the parent study and a delayed FC in study 206882 in absence of rescue medication after end of treatment in the parent study Timeframe: Up to Month 57 7. Time to loss of FC from time of achieving delayed FC in Not-on-NA participants with a partial response in the parent study and a delayed FC in study 206882 Timeframe: From date of achieving delayed FC up to Month 57 8. Percentage of On-NA participants with a partial response in the parent study, who discontinue NA treatment in study 206882, and have a delayed FC in 206882 in absence of rescue medication after end of treatment in the parent study Timeframe: Up to Month 57 9. Time to loss of FC in On-NA participants who achieve a partial response in the parent study, discontinue NA treatment in study 206882 and achieve delayed FC in 206882 Timeframe: From date of achieving delayed FC up to Month 57 10. Percentage of On-NA participants with a partial response in the parent study, who do not discontinue NA treatment in study 206882, and have a delayed treatment response in 206882 in absence of rescue medication after end of treatment in the parent study Timeframe: Up to Month 33 11. Time to loss of treatment response in On-NA participants who achieve a partial response in the parent study, do not discontinue NA treatment in study 206882 and have a delayed treatment response in 206882 Timeframe: From date of achieving delayed treatment response up to Month 33 12. Percentage of On-NA participants with a partial response in the parent study, who discontinue NA treatment in study 206882, and have HBsAg loss in the absence of any rescue medication after NA cessation in 206882 Timeframe: From Month 3 to Month 57 13. Percentage of On-NA participants with a partial response in the parent study, who discontinue NA treatment in study 206882, and have virologic relapse or use of any rescue medication after NA cessation in 206882 Timeframe: From Month 3 up to Month 57 14. Percentage of On-NA participants with a partial response in the parent study, who discontinue NA treatment in study 206882, and have clinical relapse or use of any rescue medication after NA cessation in 206882 Timeframe: From Month 3 up to Month 57 15. Percentage of On-NA participants with a partial response in the parent study, who discontinue NA treatment in study 206882 and have use of any rescue medication after NA cessation in 206882 Timeframe: From Month 3 up to Month 57 16. Percentage of participants with anti-HBs (antibody to HBsAg) Timeframe: Up to 57 months 17. Percentage of participants with anti-HBe (antibody to hepatitis B e-antigen \[HBeAg\]) Timeframe: Up to 57 months 18. Absolute values for HBsAg, hepatitis B virus (HBV) deoxyribonucleic acid (DNA), HBeAg (logarithm to the base 10 \[log10\] international units per milliliter \[IU/mL\]) Timeframe: Up to 57 months 19. Change from Baseline for HBsAg, HBV DNA, HBeAg (log10 IU/mL) Timeframe: Baseline (End of Study visit in the parent study) and up to 57 months 20. Absolute values for hepatitis B core-related antigen (HBcrAg) (kiloUnits per milliliter \[kU/mL\]) Timeframe: Up to 57 months 21. Change from Baseline for HBcrAg (kU/mL) Timeframe: Baseline (End of Study visit in the parent study) and up to 57 months 22. Absolute values for HBV ribonucleic acid (RNA) (log10 IU/ml) Timeframe: Up to 57 months 23. Change from Baseline for HBV RNA (log10 IU/ml) Timeframe: Baseline (End of Study visit in the parent study) and up to 57 months 24. Percentage of participants with mutations Timeframe: Up to 57 months Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT04954859) ## Eligibility **Sex** All **Age groups** Adults, Older adults **Minimum age** 18 Years **Healthy volunteers** No ### Inclusion criteria - Participants who enter the study on stable NA are willing and able to cease their NA treatment in accordance with the NA cessation schedule. - Capable of giving informed consent. For participants rolling over from 209668 (B-Clear), 209348 (B-Together), and 212602 (B-Fine): - Participants who have previously received at least one dose of bepirovirsen AND 1. Achieved the PSPO in the parent study and who maintained a response until the End of Study (EoS) visit in their parent study (defined as complete responders to bepirovirsen from the parent study) OR 2. Demonstrated hepatitis B virus surface antigen (HBsAg) reduction greater than or equal to (≥) 1.0 log10 international units per milliliter (IU/mL) from parent study Baseline with HBsAg levels less than (<) 100 IU/mL and HBV deoxyribonucleic acid (DNA) < lower limit of quantification (LLOQ) for 24 weeks after the actual end of treatment regimen, in the absence of rescue medication and maintained until their EoS visit in the parent study. For participants rolling over from 202009 (B-Well1) and 219288 (B-Well 2): - Participants who have previously received at least 1 dose of bepirovirsen (or matching placebo where appropriate) AND 1. NA cessated at Week 48 in parent study and achieved at least HBsAg <1 IU/ml and HBV DNA