Bepirovirsen Delivers 19% Cure Rate, 26% in Low HBsAg Subgroup
IONS•Phase III B-Well studies showed that 19% of chronic hepatitis B patients receiving bepirovirsen achieved a functional cure versus 0% with placebo. In the subgroup with low HBsAg levels—about 45% of CHB patients—26% maintained viral suppression six months post-treatment, with decisions expected from regulators in Q3 2026.
1. Phase III B-Well Trial Outcomes
Pooled data from the B-Well 1 and B-Well 2 studies revealed that 19% of participants receiving six months of bepirovirsen achieved a functional cure—undetectable virus six months post-treatment—while no placebo recipients reached this benchmark.
2. Enhanced Efficacy in Low HBsAg Patients
Among the approximately 45% of CHB patients with low HBsAg levels, 26% attained sustained viral suppression six months after stopping therapy, highlighting greater benefit in this subgroup.
3. Safety and Tolerability Findings
Bepirovirsen showed an acceptable safety profile, with the most common adverse events being injection site redness, localized pain and temporary elevations in liver enzymes.
4. Regulatory Review and Market Implications
Regulatory decisions in the US, EU and Japan are anticipated in Q3 2026, and experts project bepirovirsen could transform the hepatitis B market by significantly improving on current nucleotide analogue therapies, which deliver functional cures in around 1% of patients.
