B-Clear Phase 2b Study Design: Establishing the Efficacy and Safety of Bepirovirsen in Patients with Chronic Hepatitis B Virus Infection.
Adv Ther 2023;
40:4101-4110. [PMID:
37393402 PMCID:
PMC10427703 DOI:
10.1007/s12325-023-02531-z]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/25/2023] [Indexed: 07/03/2023]
Abstract
INTRODUCTION
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.
METHODS
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.
PLANNED OUTCOMES
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.
TRIAL REGISTRATION NUMBER
ClinicalTrials.gov (NCT04449029; GSK study 209668).
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