# Brii Bio Presents Late-Breaking Data from Its Phase 2 ENSURE Study at EASL Congress 2026, Further Supporting the Potential Role of BRII-179 in Achieving Durable Immunological Control of HBV

- Link: https://www.thailand-business-news.com/pr-news/brii-bio-presents-late-breaking-data-from-its-phase-2-ensure-study-at-easl-congress-2026-further-supporting-the-potential-role-of-brii-179-in-achieving-durable-immunological-control-of-hbv
- Published: 2026-05-27T18:00:00+07:00
- Author: PR Newswire

–_ Final results from the ENSURE study demonstrate that the addition of elebsiran
resulted in a higher functional cure rate compared with pegylated interferon alfa(
PEG-IFNα) alone_

_–__ Data from Cohort 4 suggested that participants responding to prior BRII__‑__179
treatment achieved the most robust functional cure outcomes, further supporting 
its potential clinical benefit_

_–__ Data from_ _an ENSURE translational study demonstrated that BRII__‑__179-induced
epitope-mismatched CD4+ T_ _cells and HBs__‑__specific B_ _cell maturation were 
associated with enhanced HBsAg loss following curative treatment, offering additional
insights into its potential mechanisms_

DURHAM, N.C. and BEIJING, May 27, 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-study (EOS) data from Cohorts 1-4 of its Phase 2 ENSURE
study at the European Association for the Study of the Liver (EASL) Congress 2026
in Barcelona, Spain.

The ENSURE study (NCT05970289) is a multicenter, open-label Phase 2 study in the
Asia-Pacific region. Cohorts 1-3 were designed to evaluate the contribution of elebsiran,
an investigational small interfering ribonucleic acid (siRNA), to the combination
treatment with PEG-IFNα in participants with chronic hepatitis B virus (HBV) infection
with baseline hepatitis B surface antigen (HBsAg) of 100-3,000 IU/mL.

Cohort 4 evaluated a novel sequential combination treatment strategy for HBV utilizing
Brii Bio’s therapeutic vaccine, BRII-179, to prime and enrich participants with 
a goal of improving responsiveness to curative therapies. Participants previously
treated with 9 doses of BRII-179 and elebsiran in the prior Phase 2 study BRII-179-
835-001 (NCT04749368) were enrolled and received 48 weeks of combination treatment
with elebsiran and PEG-IFNα. These participants were categorized as BRII-179 anti-
HBs responders or non-responders based on whether their peak hepatitis B surface
antibody (anti-HBs) titers exceeded 10 IU/L during the prior study.  

All participants were maintained on nucleos(t)ide analogues (NAs) for an additional
24 weeks upon completion of PEG-IFNα + elebsiran treatment. Functional cure rates
at the end of ENSURE study, defined as sustained HBsAg loss with undetectable HBV
DNA for at least 24 weeks after stopping all treatment, including NAs, are presented.
Final results demonstrated that the HBsAg loss benefit observed in the elebsiran
and PEG-IFNα combination cohorts translated into a higher functional cure rate compared
to the PEG-IFNα alone cohort. BRII-179-experienced participants achieved higher 
functional cure rates, particularly among anti-HBs responders, suggesting that BRII-
179 may play an important role in achieving durable immunological control of HBV.

Brii Bio is conducting two additional Phase 2b trials to further define the role
of BRII-179 in the treatment of chronic HBV infection and to optimize combination
regimens for pivotal studies. The ENRICH study is evaluating the role of BRII-179
in priming HBV-specific immunity and identifying immuno-responsive patients with
a higher likelihood of achieving functional cure. The ENHANCE study consists of 
two parts: one evaluating concurrent triple combination therapy with BRII-179, elebsiran
and PEG-IFNα for 48 weeks, and another evaluating a sequential regimen of BRII-179
and elebsiran for 24 weeks followed by triple combination therapy for 24 weeks. 
End-of-treatment (EOT) data from both studies are expected to be presented in 2026.

"We are encouraged by the consistency of the findings observed throughout the ENSURE
study and believe these final results highlight the potential of BRII-179 and elebsiran
in improving functional cure outcomes," said David Margolis, M.D., Chief Medical
Officer of Brii Bio. "Together with upcoming data from our ongoing studies, these
results provide important insights to guide the future development of our HBV functional
cure program."

Details of the late-breaker poster presentation are as follows:

**Title:** Functional cure rate in chronic hepatitis B virus infected participants
receiving elebsiran and pegylated interferon alfa: final results from the phase 
2 ENSURE study

**Session/Presentation Type:** Late-breaker posters

**Session Time:** May 27, 08:30 – May 30, 16:00 (UTC+1)

**Abstract** **Number/Identifier:** LB26-5012/ LBP-040

**Presenter:** Grace Lai-Hung Wong, MBChB (CUHK), MD (CUHK), FRCP (Lond, Edin), 
FHKCP, FHKAM (Medicine), Professor of Gastroenterology and Hepatology at CUHK Medical
Data Analytics Centre (MDAC) and Department of Medicine and Therapeutics in Hong
Kong SAR, China

 ◦ At Week 72 (24 weeks post EOT), 19 of 20 participants who achieved HBsAg loss
   met NA discontinuation criteria and stopped NA for the additional 24-week follow-
   up; One participant remained HBeAg positive.
 ◦ In Cohorts 1-3, functional cure was achieved in 2/19 (10.5%) and 3/18 (16.7%)
   participants from the elebsiran 200 mg or 100 mg + PEG-IFNα cohorts, respectively,
   compared with 1/18 (5.6%) in the PEG-IFNα cohort. In Cohort 4, functional cure
   was achieved in 8/31 (25.8%) participants, including 7/19 (36.8%) among anti-
   HBs responders compared with 1/12 (8.3%) among non-responders.
 ◦ Although all participants achieving functional cure had a baseline HBsAg levels
   below 1,000 IU/mL in the ENSURE study, 4/7 (57.1%) of anti-HBs responders achieving
   functional cure had baseline HBsAg levels between 1,154 and 3,086 IU/mL at enrollment
   in the prior BRII-179-835-001 study.
 ◦ After NA discontinuation, no new treatment-related adverse events (TRAE) were
   reported. Most TRAEs resolved during the post EOT follow-up period.
 ◦ Participants achieving sustained HBsAg loss through combination therapy demonstrated
   favorable off-NA outcomes, characterized by infrequent HBV DNA rebound and no
   ALT elevations.

In a separate oral presentation, Dr. Nina Le Bert will report findings from a translational
study evaluating immunological responses associated with BRII‑179 using samples 
from the ENSURE and prior BRII-179-835-001 trials. The study identified a novel 
mechanism whereby BRII‑179 induced CD4+ T‑cell response targeting epitope sequences
in the Pre-S1 region that are mismatched to circulating HBV genotypes. These vaccine‑
induced T cells remained functionally stable for over two years, persisted during
subsequent PEG-IFNα and siRNA treatment. Notably, these T‑cell responses were associated
with progressive maturation of HBs‑specific B cells during treatment, an effect 
linked to enhanced HBsAg loss rates. These findings provide new insights into the
potential mechanisms underlying BRII‑179–mediated functional cure.

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/).

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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%2520are%252087%2520million%2520people,living%2520with%2520chronic%2520hepatitis%2520C.%23:~:text=Thereare87millionpeople,livingwithchronichepatitisC.)

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