B-Clear Phase 2b Study Design: Establishing the Efficacy and Safety of Bepirovirsen in Patients with Chronic Hepatitis B Virus Infection.

Bepirovirsen (GSK3228836) is an antisense oligonucleotide that induced rapid and prolonged hepatitis B surface antigen (HBsAg) reduction with a favorable safety profile following 4 weeks of treatment in participants with chronic hepatitis B virus (HBV) infection. The objective of the phase 2b study B-Clear is to access the efficacy and safety of bepirovirsen in participants with chronic HBV infection. B-Clear is a phase 2b, multicenter, randomized, partial-blind (sponsor/participant-blinded, investigator-unblinded) study in participants with chronic HBV infection receiving stable nucleos(t)ide analogue (On-NA) or not currently receiving NA therapy (Not-on-NA). Eligibility criteria included HBsAg > 100 IU/mL, HBV DNA < 90 IU/mL (On-NA) or > 2000 IU/mL (Not-on-NA), and alanine aminotransferase ≤ 2 × upper limit of normal (ULN; On-NA) or < 3 × ULN (Not-on-NA). Participants were randomized 3:3:3:1 to one of four treatment arms, with treatment administered weekly as subcutaneous injections with or without loading doses (LD) on days 4 and 11: bepirovirsen 300 mg (with 300 mg LD) for 24 weeks; bepirovirsen 300 mg (with 300 mg LD) for 12 weeks then bepirovirsen 150 mg for 12 weeks; bepirovirsen 300 mg (with 300 mg LD) for 12 weeks then placebo for 12 weeks; placebo for 12 weeks (with placebo LD) then bepirovirsen 300 mg without LD for 12 weeks. The primary endpoint of the study was HBsAg < lower limit of detection and HBV DNA < lower limit of quantification for 24 weeks after the end of bepirovirsen treatment in the absence of rescue medication. The study enrolled 457 participants (On-NA, n = 227; Not-on-NA, n = 230) and the last patient visit occurred in March 2022. The novel design of the B-Clear study will allow assessment of HBsAg and HBV DNA seroclearance post bepirovirsen treatment discontinuation in the presence and absence of background NA therapy. ClinicalTrials.gov (NCT04449029; GSK study 209668).

Cremer J ，Elston R ，Campbell FM ，Kendrick S ，Paff M ，Quinn G ，Theodore D ... -  《-》

Efficacy and Safety of Bepirovirsen in Chronic Hepatitis B Infection.

Bepirovirsen is an antisense oligonucleotide that targets all hepatitis B virus (HBV) messenger RNAs and acts to decrease levels of viral proteins. We conducted a phase 2b, randomized, investigator-unblinded trial involving participants with chronic HBV infection who were receiving or not receiving nucleoside or nucleotide analogue (NA) therapy. Participants were randomly assigned (in a 3:3:3:1 ratio) to receive weekly subcutaneous injections of bepirovirsen at a dose of 300 mg for 24 weeks (group 1), bepirovirsen at a dose of 300 mg for 12 weeks then 150 mg for 12 weeks (group 2), bepirovirsen at a dose of 300 mg for 12 weeks then placebo for 12 weeks (group 3), or placebo for 12 weeks then bepirovirsen at a dose of 300 mg for 12 weeks (group 4). Groups 1, 2, and 3 received loading doses of bepirovirsen. The composite primary outcome was a hepatitis B surface antigen (HBsAg) level below the limit of detection and an HBV DNA level below the limit of quantification maintained for 24 weeks after the planned end of bepirovirsen treatment, without newly initiated antiviral medication. The intention-to-treat population comprised 457 participants (227 receiving NA therapy and 230 not receiving NA therapy). Among those receiving NA therapy, a primary-outcome event occurred in 6 participants (9%; 95% credible interval, 0 to 31) in group 1, in 6 (9%; 95% credible interval, 0 to 43) in group 2, in 2 (3%; 95% credible interval, 0 to 16) in group 3, and 0 (0%; post hoc credible interval, 0 to 8) in group 4. Among participants not receiving NA therapy, a primary-outcome event occurred in 7 participants (10%; 95% credible interval, 0 to 38), 4 (6%; 95% credible interval, 0 to 25), 1 (1%; post hoc credible interval, 0 to 6), and 0 (0%; post hoc credible interval, 0 to 8), respectively. During weeks 1 through 12, adverse events, including injection-site reactions, pyrexia, fatigue, and increased alanine aminotransferase levels, were more common with bepirovirsen (groups 1, 2, and 3) than with placebo (group 4). In this phase 2b trial, bepirovirsen at a dose of 300 mg per week for 24 weeks resulted in sustained HBsAg and HBV DNA loss in 9 to 10% of participants with chronic HBV infection. Larger and longer trials are required to assess the efficacy and safety of bepirovirsen. (Funded by GSK; B-Clear ClinicalTrials.gov number, NCT04449029.).

Yuen MF ，Lim SG ，Plesniak R ，Tsuji K ，Janssen HLA ，Pojoga C ，Gadano A ，Popescu CP ，Stepanova T ，Asselah T ，Diaconescu G ，Yim HJ ，Heo J ，Janczewska E ，Wong A ，Idriz N ，Imamura M ，Rizzardini G ，Takaguchi K ，Andreone P ，Arbune M ，Hou J ，Park SJ ，Vata A ，Cremer J ，Elston R ，Lukić T ，Quinn G ，Maynard L ，Kendrick S ，Plein H ，Campbell F ，Paff M ，Theodore D ，B-Clear Study Group ... -  《-》

Safety, tolerability and antiviral activity of the antisense oligonucleotide bepirovirsen in patients with chronic hepatitis B: a phase 2 randomized controlled trial.

Chronic infection with hepatitis B virus (HBV) leads to an increased risk of death from cirrhosis and hepatocellular carcinoma. Functional cure rates are low with current treatment options (nucleos(t)ide analogs (NAs) and pegylated interferons). Bepirovirsen is an antisense oligonucleotide targeting all HBV messenger RNAs; in cell culture and animal models, bepirovirsen leads to reductions in HBV-derived RNAs, HBV DNA and viral proteins. This phase 2 double-blinded, randomized, placebo-controlled trial is the first evaluation of the safety and activity of an antisense oligonucleotide targeting HBV RNA in both treatment-naïve and virally suppressed individuals with chronic HBV infection. The primary objective was to assess the safety and tolerability of bepirovirsen in individuals with chronic hepatitis B (CHB) (NCT02981602). The secondary objective was to assess antiviral activity, including the change from baseline to day 29 in serum hepatitis B surface antigen (HBsAg) concentration. Participants with CHB infection ≥6 months and serum HBsAg ≥50 IU ml-1 were enrolled from seven centers across Hong Kong and the Republic of Korea and randomized (3:1 within each dose cohort) to receive bepirovirsen or placebo via subcutaneous injection twice weekly during weeks 1 and 2 (days 1, 4, 8 and 11) and once weekly during weeks 3 and 4 (days 15 and 22). Participants were then followed for 26 weeks. Twenty-four participants were treatment-naïve and seven were receiving stable NA therapy. Treatment-emergent adverse events were mostly mild/moderate (most commonly injection site reactions). Eleven (61.1%) and three (50.0%) treatment-naïve participants experienced one or more treatment-emergent adverse event in the bepirovirsen and placebo groups, respectively. In participants receiving NA therapy, the corresponding numbers were three (60.0%) and one (50.0%). Transient, self-resolving alanine aminotransferase flares (≥2× upper limit of normal) were observed in eight treatment-naïve participants and three participants on stable NA regimens in the bepirovirsen treatment arms. HBsAg reductions were observed and were significant versus placebo for treatment-naïve participants receiving bepirovirsen 300 mg (P = 0.001), but not for the bepirovirsen 150 mg group (P = 0.245) or participants receiving stable NA therapy (P = 0.762). Two participants in each of the 300 mg dose groups achieved HBsAg levels below the lower limit of quantitation by day 29 (n = 3) or day 36 (n = 1). Bepirovirsen had a favorable safety profile. These preliminary observations warrant further investigation of the safety and activity of bepirovirsen in a larger CHB patient population.

Yuen MF ，Heo J ，Jang JW ，Yoon JH ，Kweon YO ，Park SJ ，Tami Y ，You S ，Yates P ，Tao Y ，Cremer J ，Campbell F ，Elston R ，Theodore D ，Paff M ，Bennett CF ，Kwoh TJ ... -  《-》

Phase IIa, randomised, double-blind study of GSK3389404 in patients with chronic hepatitis B on stable nucleos(t)ide therapy.

Bepirovirsen, an antisense oligonucleotide targeting pregenomic and mRNA transcripts of HBV, has been conjugated to N-acetyl galactosamine (GSK3389404) to enhance hepatocyte delivery. This dose-finding study was the first to assess GSK3389404 for chronic HBV infection. This phase IIa, randomised, double-blind, placebo-controlled, 2-part study was conducted in 22 centres in Asia (NCT03020745). Pharmacokinetic findings from Part 1 informed Part 2 dosing. In Part 2, patients with chronic hepatitis B on nucleos(t)ide analogue therapy were randomised 11:2 to GSK3389404 (30, 60, 120 mg weekly or 120 mg bi-weekly) or placebo until Day 85. Coprimary endpoints included HBsAg response (≥1.5 log10 IU/ml reduction from baseline) rate, safety and pharmacokinetics. Parts 1 and 2 included 12 (9 GSK3389404, 3 placebo) and 66 patients (56 GSK3389404, 10 placebo), respectively. In Part 2, one patient each in the 60 mg weekly, 120 mg weekly and 120 mg bi-weekly arms achieved a HBsAg response. HBsAg reductions were dose-dependent (Day 85: mean 0.34 [60 mg weekly] to 0.75 log10 IU/ml [120 mg weekly]) and occurred in hepatitis B e antigen-positive and -negative patients. No patient achieved HBsAg seroclearance. 43/56 (77%) GSK3389404- and 9/10 (90%) placebo-treated patients reported adverse events. No deaths were reported. Alanine aminotransferase flares (>2x upper limit of normal) occurred in 2 GSK3389404-treated patients (120 mg weekly, 120 mg bi-weekly); both were associated with decreased HBsAg, but neither was considered a responder. GSK3389404 plasma concentrations peaked 2-4 hours post dose; mean plasma half-life was 3-5 hours. GSK3389404 showed an acceptable safety profile and target engagement, with dose-dependent reductions in HBsAg. However, no efficacious dosing regimen was identified. NCT03020745. Hepatitis B virus (HBV) can result in chronic HBV infection, which may ultimately lead to chronic liver disease, primary liver cancer and death; HBV proteins may prevent the immune system from successfully controlling the virus. GSK3389404 is an investigational agent that targets HBV RNA, resulting in reduced viral protein production. This study assessed the safety of GSK3389404 and its ability to reduce the viral proteins in patients with chronic HBV infection. GSK3389404 showed dose-dependent reduction in hepatitis B surface antigen, with an acceptable safety profile. While no clear optimal dose was identified, the findings from this study may help in the development of improved treatment options for patients with chronic HBV infections.

Yuen MF ，Heo J ，Kumada H ，Suzuki F ，Suzuki Y ，Xie Q ，Jia J ，Karino Y ，Hou J ，Chayama K ，Imamura M ，Lao-Tan JY ，Lim SG ，Tanaka Y ，Xie W ，Yoon JH ，Duan Z ，Kurosaki M ，Park SJ ，Labio ME ，Kumar R ，Kweon YO ，Yim HJ ，Tao Y ，Cremer J ，Elston R ，Davies M ，Baptiste-Brown S ，Han K ，Campbell FM ，Paff M ，Theodore D ... -  《-》

Bepirovirsen (GSK3228836) in chronic hepatitis B infection: an evaluation of phase II progress.

Mak LY ，Hui RW ，Fung J ，Seto WK ，Yuen MF ... -  《-》