Sino Biopharmaceutical Limited Presents Data From Two Phase III Clinical Trials Of Bepirovirsen At EASL 2026

Sino Biopharmaceutical Limited announced that positive pivotal data for bepirovirsen, jointly developed by Chia Tai Tianqing Pharmaceutical Group Co., Ltd. and GSK plc, for the treatment of chronic hepatitis B was presented. The results from two Phase III clinical trials, B-Well 1 (NCT05630807) and B-Well 2 (NCT05630820), were simultaneously published in the New England Journal of Medicine and presented at the 2026 European Association for the Study of the Liver Congress. The data on regional subgroups was also presented in an oral session at the EASL.

In particular, the data from the Chinese subgroup showed that among subjects with HBsAg = 3000 IU/ml, the functional cure rate was 24%; among subjects with HBsAg = 1000 IU/ml, the functional cure rate reached 35%. The results from the two trials are summarised as follows: Functional cure rates at Week 72 in B-Well 1 and B-Well 2 by patient segment: Functional cure response rate at Week 72 of the B-Well trials, 6 months after discontinuing all treatments: Primary confirmatory endpoint: 19% vs. 0% (placebo) 233 of 1,220 vs.

0 of 614; B-Well 1: 20% vs. 0% [127 of 650 vs. 0 of 328]; B-Well 2: 19% vs.

0% [106 of 570 vs. 0 of 286]. Ranked secondary endpoint: 26% vs.

0% (placebo) 200 of 768 vs. 0 of 393; B-Well 1: 25% vs. 0% [105 of 426 vs.

0 of 214]; B-Well 2: 28% vs. 0% [95 of 342 vs. 0 of 179].

Pooled data from both trials showed that 6-month treatment with bepirovirsen achieved a statistically significant and clinically meaningful 19% functional cure response rate (233 of 1,220 vs. 0 of 614 in the placebo group, with p<0.001 in both trials) in the overall study population (adults with =3000 IU/ml hepatitis B surface antigen (HBsAg) level), meeting the primary endpoint. In a key secondary endpoint, a functional cure rate of 26% (200 of 768 vs.

0 of 393 in the placebo group, with p < 0.001 in both trials) was achieved in participants with = 1,000 IU/ml HBsAg level, a group that represents approximately 45% of diagnosed chronic hepatitis B cases globally. The current standard of care typically requires lifelong therapy, with functional cure rates achieved in less than 1% of patients. Functional cure occurs when the hepatitis B virus DNA and HBsAg are undetectable in the blood for at least 6 months after stopping all treatments.

This indicates the disease is controlled by the immune system without medication. A loss in HBsAg is also associated with an 89% reduction in risk of liver cancer and a 62% reduction in risk of all-cause mortality. Notably, in an exploratory analysis, 49% of bepirovirsen recipients achieved a quantitative hepatitis B surface antigen of =100 IU/mL one year after the end of treatment.

Medical literature has linked this level of low surface antigen with increased immune control and improved patient outcomes. Moreover, 23% of all bepirovirsen recipients (283 of 1,220 vs. 0 of 614 in the placebo group; p<0.001 in both trials) and 31% of bepirovirsen recipients with baseline HBsAg =1000 IU/mL (237 of 768 vs.

0 of 393 in the placebo group; p<0.001 in both trials) achieved a sustained hepatitis B virus DNA lower limit of quantification (

The absolute values are being presented bepirovirsen group vs. placebo group. The trials showed an acceptable safety and tolerability profile consistent with other studies of bepirovirsen.

The three most frequently observed adverse events were injection site erythema, local pain and temporary rise in the blood level of a liver enzyme. Bepirovirsen is currently under review by regulatory authorities in China (Breakthrough Therapy and Priority Review designation granted), the United States (Priority review, Breakthrough Therapy and Fast Track Designation granted), Europe, and Japan (SENKU designation granted). GSK anticipates to receive the regulatory decision from the China?s National Medical Products Administration in the first half of 2027, and launch preparations are underway.

The B-Well 1 and B-Well 2 trials are global multi-centre, randomised, double-blind, placebo-controlled trials conducted in 29 countries. They assessed the efficacy, safety, pharmacokinetic profile and durability of functional cure in nucleos(t) ide analogue-treated adult participants with chronic hepatitis B and baseline surface antigen (HBsAg) =3000 IU/ml. The primary endpoint assessed the proportion of participants achieving functional cure in patients with baseline HBsAg =3000 IU/ml.

A key ranked secondary endpoint evaluated functional cure in participants with baseline HBsAg =1000 IU/ml. Functional cure is defined as HBsAg being undetectable in the blood for at least 24 weeks after stopping all treatments, indicating that the disease is controlled by the immune system without medication.