# Brii Bio Announces Topline End-of-Treatment Data from Phase 2b ENRICH and ENHANCE Studies for the Treatment of Chronic Hepatitis B

- Link: https://www.thailand-business-news.com/pr-news/brii-bio-announces-topline-end-of-treatment-data-from-phase-2b-enrich-and-enhance-studies-for-the-treatment-of-chronic-hepatitis-b
- Published: 2026-07-03T07:00:00+07:00
- Author: PR Newswire

◦ _End-of-treatment data from ENRICH demonstrated higher HBsAg loss rates, consistent
   with ENSURE Cohort 4, confirming the role of BRII-179 in priming immune responses
   for functional cure strategies_
 ◦ _End-of-treatment data from ENHANCE did not demonstrate improved HBsAg loss rates
   compared to ENSURE Cohorts 2 and 3, informing selection of combination regimen
   going forward_
 ◦ _As previously disclosed, advancement of ENRICH into Phase 3 remains subject 
   to the outcome of arbitration with Vir Biotechnology regarding the elebsiran 
   manufacturing technology transfer _

DURHAM, N.C. and BEIJING, July 3, 2026 /PRNewswire/ — [Brii Biosciences Limited](https://www.briibio.com/en/)("
Brii Bio" or the "Company", stock code: 2137.HK), a biotechnology company developing
therapies to improve patient health and choice across diseases with high unmet medical
need, today announced end-of-treatment (EOT) results from its ongoing Phase 2b ENRICH
and ENHANCE studies investigating sequential versus concurrent combination regimens
of BRII-179 with elebsiran and PEG-IFNα for chronic hepatitis B virus (HBV) infection.

The ENRICH and ENHANCE studies are two Phase 2b studies designed to further define
the role of BRII-179 in chronic HBV treatment and to select the optimal combination
regimen for future development. The ENRICH study evaluates BRII-179 as a priming
therapy administered prior to elebsiran and PEG-IFNα treatment. The ENHANCE study
evaluates a concurrent triple combination regimen of BRII-179, elebsiran, and PEG-
IFNα to enhance the functional cure rates.

At EOT, the ENRICH study evaluating pre-treatment with BRII-179 followed by elebsiran
and PEG-IFNα demonstrated hepatitis B surface antigen (HBsAg) loss rates of 42.9%(
42/98) and 40.0% (20/50) across two different BRII-179 dosing schedules, being 5
doses administered once every 3 weeks versus 7 doses administered once every 2 weeks,
respectively. These results were consistent with the HBsAg loss rate observed in
ENSURE Cohort 4, 41.9% (13/31) in patients with prior BRII-179 treatment, supporting
the immune priming role of BRII-179. The Company had engaged with the Center for
Drug Evaluation of the National Medical Products Administration of China and reached
preliminary alignment regarding a potential registrational study.

At EOT, the ENHANCE (Part A-1) study evaluating a concurrent triple combination 
did not demonstrate improved HBsAg loss rates compared with ENSURE Cohorts 2 and
3, 29.7% (11/37), with an observed rate of 25.5% (25/98). However, higher HBsAg 
loss rates were observed compared with the PEG-IFNα control arm, 10.2% (5/49).

Subgroup analyses from the ENRICH study suggest potential differentiation in subjects
with higher baseline HBsAg levels (1000-3000 IU/mL), consistent with prior findings
from ENSURE Cohort 4, indicating that BRII-179 may induce beneficial immune responses
regardless of baseline HBsAg levels in this difficult-to-treat population.

The ENHANCE study, Part A-2, also evaluated a sequential approach designed to potentially
shorten PEG-IFNα therapy by administering BRII-179 plus elebsiran during the first
24 weeks followed by 24 weeks of elebsiran and PEG-IFNα. At EOT, this combination
regimen achieved an HBsAg loss rate of 22.5% (18/80), suggesting full course of 
PEG-IFNα therapy is needed for optimal curative outcome.

HBsAg loss is an important endpoint when evaluating functional cure regimens, but
requires confirmation during off-treatment follow-up to assess rebound and durability
of functional cure. No new safety concerns were identified in either study. The 
Company plans to present detailed data, including additional efficacy, safety, subgroup
analyses and follow-up results, at a scientific conference in the second half of
2026.

"These initial EOT data provide important insights into the relative performance
of the ENRICH and ENHANCE study designs," said Dr. David Margolis, M.D., the Chief
Medical Officer of the Company. "While longer-term follow-up is needed to assess
durability of the HBsAg loss, the data observed to date, together with EOT and post-
EOT findings from multiple prior studies, are very consistent, suggesting that the
ENRICH study design is preferred for a registrational study. We look forward to 
sharing the more complete dataset later this year."

As previously disclosed, in light of the ongoing arbitration between the Company
and Vir Biotechnology, Inc., and the unknown nature and timing of the outcome of
the Arbitration or any mutual resolution of the claims, the Company considers the
future of the elebsiran program to be uncertain. In particular, the Company cannot
invest in a Phase 3 clinical study of any elebsiran-containing combination therapy
for HBV unless and until the claims in the Arbitration are satisfactorily resolved.
The Company will continue to evaluate such developments and assess their impact 
on the continued viability of the elebsiran program, and update its shareholders
and the public as and when appropriate in accordance with relevant requirements.

For more information about Brii Bio’s HBV programs visit [www.briibio.com](https://www.briibio.com/en/).

**About Hepatitis B**

Hepatitis B virus (HBV) infection is one of the world’s most significant infectious
disease threats with more than 254 million people infected globally.^([1]) Chronic
HBV infection is the leading cause of liver disease and an estimated 820,000 people
die of complications from chronic HBV infection each year.^(1) HBV is of exceptional
concern in China, where 87 million people are chronically infected.^([2])

**About BRII-179**

BRII-179 is a novel recombinant protein-based HBV immunotherapeutic candidate that
expresses the Pre-S1, Pre-S2, and S HBV surface antigens, designed to induce enhanced
and broad B-cell and T-cell immunity. In November 2023, the Center for Drug Evaluation(
the "CDE") of China’s National Medical Products Administration (the "NMPA") granted
BRII-179 Breakthrough Therapy Designation.

**About** **Elebsiran**

Elebsiran is an investigational subcutaneously administered HBV-targeting siRNA 
designed to degrade HBV RNA transcripts and limit the production of hepatitis B 
surface antigen. It has the potential to have direct antiviral activity against 
HBV and HDV. It is the first siRNA in the clinic to include Enhanced Stabilization
Chemistry Plus technology to enhance stability and minimize off-target activity,
which potentially can result in an increased therapeutic index. Brii Bio licensed
exclusive rights to develop and commercialize elebsiran for the Greater China territory
from Vir Biotechnology, Inc. in 2020. In May 2024, the CDE of China’s NMPA granted
elebsiran Breakthrough Therapy Designation.

**About Brii Bio**

Brii Biosciences Limited ("Brii Bio", stock code: 2137.HK) is a biotechnology company
developing therapies to improve patients’ health by addressing high unmet medical
needs with limited treatment options. The Company is advancing a broad pipeline 
of unique therapeutic candidates with lead programs against hepatitis B virus (HBV)
infection. The Company is led by a visionary and experienced leadership team and
has operations in both China and the United States. For more information, visit 
[www.briibio.com](https://www.briibio.com/en/).

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^(1) World Health Organization. (April 2024). Global hepatitis report 2024: action for access in low- and middle-income countries. World Health Organization. Retrieved from [https://www.who.int/publications/i/item/9789240091672](https://www.who.int/publications/i/item/9789240091672)

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^(2) World Health Organization. Hepatitis. World Health Organization. Retrieved from [https://www.who.int/china/health-topics/hepatitis#:~:text=There%20are%2087%20million%20people,living%20with%20chronic%20hepatitis%20C](https://www.who.int/china/health-topics/hepatitis#:~:text=There%20are%2087%20million%20people,living%20with%20chronic%20hepatitis%20C)[.](https://www.who.int/china/health-topics/hepatitis#:~:text=There%2520are%252087%2520million%2520people,living%2520with%2520chronic%2520hepatitis%2520C.%23:~:text=Thereare87millionpeople,livingwithchronichepatitisC.)

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