GSK reported Phase 3 efficacy for bepirovirsen, an antisense oligonucleotide targeting hepatitis B virus transcripts, with a functional cure rate of about 19% across two trials after discontinuation of background nucleos(t)ide analog therapy. In both B-Well 1 and B-Well 2, placebo arms showed no patients meeting the functional cure endpoint. The NEJM-published data describe pooled week-72 outcomes and a higher adverse-event burden in the bepirovirsen groups, including more grade 3 alanine aminotransferase elevations. GSK characterized the results as a potential step-change in chronic hepatitis B therapy. The readouts follow earlier license and development momentum for bepirovirsen, with regulatory review activity in multiple jurisdictions referenced alongside the data release.