Advancing HBV Functional Cure Toward Key Phase 2b Data Readouts

Increasing Discovery Efforts to Drive Long-term Value Creation

Strong Cash Position Supporting Strategic Priorities

Upcoming Conference Calls: 
English Session: March 20 at 8:30 p.m. HKT / 8:30 a.m. ET 
Chinese Session: March 20 at 8:30 a.m. HKT / March 19 at 8:30 p.m. ET

DURHAM, N.C. and BEIJING, March 19, 2026 /PRNewswire/ -- Brii Biosciences Limited ("Brii Bio," "Brii," 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 provided a corporate update and reported its financial results for the full year ended December 31, 2025.

2025 marked a year of strong execution and strategic progress for Brii Bio, with continued advancement of its late-stage hepatitis B virus (HBV) portfolio toward higher functional cure rates. The Company presented 24-week post end of treatment (EOT) follow-up data from Cohort 4 of its ongoing Phase 2b ENSURE study at the American Association for the Study of Liver Diseases (AASLD) The Liver Meeting^®, with simultaneous publication in Nature Medicine. These results support the potential of BRII-179 to improve functional cure outcomes across diverse patient populations. Leveraging insights from the ENSURE Cohort 4, Brii Bio amended the ENHANCE study protocol to evaluate an alternative triple combination regimen aimed at reducing the duration of pegylated interferon alpha (PEG-IFNα) treatment while maintaining efficacy. The confirmatory Phase 2b ENRICH and ENHANCE studies are now fully enrolled, with results expected to be announced in 2H 2026.

Alongside its HBV cure programs, Brii Bio has expanded its discovery efforts under the leadership of Chief Scientific Officer Dr. Brian Johns, who joined the Company in 2024. The Company has established robust in-house discovery capabilities, supported by an experienced discovery team, and wet lab operations in both Beijing and Shanghai. These capabilities leverage China's strong drug discovery ecosystem anchored by both innovation and execution efficiency to advance Brii Bio's early-stage pipeline while driving long-term value creation. The Company plans to disclose additional details on its discovery strategy and pipeline later this year.

Aligned with its evolving mission and strategy, the Company maintained disciplined financial management in 2025, including targeted adjustments to its operating structure and compensation framework to better align management incentives with long-term shareholder interests and business performance. Together with prudent capital allocation, the actions supported a strong cash position of US$276.1 million as of December 31, 2025, providing financial flexibility to advance both the Company's HBV functional cure programs and growing discovery pipeline.

"2025 was a year of strong execution for Brii Bio as we continued to advance our HBV functional cure strategy," said Dr. Zhi Hong, Chairman and Chief Executive Officer of Brii Bio. "The publication of our ENSURE study data in Nature Medicine underscores the scientific rigor behind our clinical approach and our long-standing commitment to improving outcomes for patients with chronic hepatitis B. At the same time, we strengthened our discovery capabilities to enable future pipeline expansion. By balancing near-term execution with long-term innovation, we are positioning the Company for durable portfolio growth and value creation."

Clinical Program Updates

HBV Program

Brii Bio continues to advance its HBV pipeline with a strong focus on achieving higher rates of functional cure through novel combination regimens. The Company is progressing multiple ongoing Phase 2b combination studies (ENSURE, ENRICH and ENHANCE) evaluating its differentiated HBV therapeutics, including elebsiran, an HBV-targeting siRNA, and BRII-179, a recombinant protein-based HBV immunotherapeutic. 

• The Phase 2b ENSURE study is designed to assess the safety and efficacy of combination approaches aimed at improving functional cure outcomes.  Cohorts 1-3 evaluate elebsiran in combination with PEG-IFNα compared to PEG-IFNα monotherapy, while Cohort 4 evaluates the potential role of BRII-179 in identifying immunologically responsive patients and improving hepatitis B surface antigen (HBsAg) loss rates.
  
  In 2025, Cohort 4 demonstrated encouraging results with BRII-179.  Key data were presented at major international liver congresses including Asian Pacific Association for the Study of the Liver (APASL), the European Association for the Study of the Liver (EASL) Congress and AASLD The Liver Meeting^®, reinforcing BRII-179's potential to contribute to functional cure improvements for chronic hepatitis B.
  
  Key findings included:

- Median baseline [range] HBsAg were numerically higher in BRII-179-induced anti-HBs responders (520 [34-2,165] IU/mL) compared with non-responders (185 [51-672] IU/mL).

- At 24 weeks post end of treatment (EOT), HBsAg loss was observed in 42.1% (8/19) of BRII-179-induced anti-HBs responders compared with 8.3% (1/12) of non-responders.

- While all participants with sustained HBsAg loss had baseline HBsAg below 1,500 IU/mL in the ENSURE study, 50% (4/8) of anti-HBs responders had baseline HBsAg levels between 1,514 and 3,086 IU/mL when enrolled in the previous study, suggesting BRII-179 may induce anti-HBs responses across a broader range of baseline HBsAg levels.

Long-term follow-up data from the ENSURE study are expected in 1H 2026 and will be presented at a future scientific conference.

• To further define the role of BRII-179 in HBV treatment and identify an optimal combination regimen for potential registrational development, the Company is evaluating BRII-179 in two additional ongoing Phase 2b studies.

- ENRICH Study: Evaluates the role of BRII-179 in priming HBV-specific immune responses and/or identifying immunologically responsive patients with a higher likelihood of achieving functional cure.

- ENHANCE Study: Evaluates a triple combination treatment regimen of BRII-179 and elebsiran plus PEG-IFNα to enhance the functional cure rate. Based on insights from ENSURE Cohort 4, the study protocol was amended to assess a simplified triple combination regimen designed to shorten PEG-IFNα treatment duration to 24 weeks.

All studies are now fully enrolled, with data from both the ENRICH and ENHANCE studies expected to be announced in 2H 2026.

• In parallel, the Company has engaged with the Center for Drug Evaluation (CDE) of National Medical Products Administration (NMPA) to discuss potential Phase 3 study designs and primary endpoints. Results from the ongoing ENRICH and ENHANCE studies are expected to inform future registrational development decisions.

Additional Clinical Programs

• In July 2025, Brii Bio announced a strategic out-licensing agreement with Joincare Group for the research, development, and commercialization of soralimixin in the Greater China region. The collaboration leverages Joincare Group's established capabilities in anti-infective therapeutics to accelerate development and maximize the commercial potential of soralimixin. The Company retains rights outside of Greater China and continues to pursue non-dilutive funding and additional partnership opportunities.
• Brii Bio is also actively seeking external partnerships to advance the development and commercialization of its long-acting candidates for treatment and prevention of HIV.

Discovery Program Updates

• By the end of 2025, Brii Bio operated a translational research laboratory in Beijing and established a state-of-the-art, fully integrated discovery laboratory in Shanghai, supported by a discovery team of experienced industry professionals. Leveraging its global R&D footprint across China and the United States, Brii Bio aims to combine the innovation and execution efficiency of China-based R&D with deep global expertise in drug discovery and development. This operating model enables rapid translation of scientific insights into testable therapeutic hypotheses, efficient target selection, and consistent advancement of early-stage programs through key discovery milestones.
• In December, Brii Bio announced its collaboration with OpenBench, leveraging its artificial intelligence (AI) platform to accelerate the Company's discovery efforts.
• Additional updates on Brii Bio's new discovery programs are expected throughout 2026 as we advance towards the clinic.

Other Corporate Updates

As part of its continued focus on strengthening alignment between management incentives and long-term shareholder interests, the Board approved a reduction plan for senior management's annual bonus arrangements for 2025 and 2026. Under this plan, in each of these years, the Company's total compensation expense for executive annual bonuses will be significantly reduced to approximately one-quarter of the original level. This action reinforces the Company's commitment to disciplined financial management and aligns management compensation more closely with business performance, capital market outcomes, and long-term shareholder value creation.

Outlook

Looking ahead, the Company remains focused on disciplined execution and continued innovation to advance both its late-stage HBV programs and early-stage discovery efforts. Clinical data readouts from the Phase 2b ENRICH and ENHANCE studies, anticipated in 2026, are expected to inform key development and registrational pathway decisions for the HBV portfolio, consistent with the Company's long-standing commitment to achieving a functional cure for chronic hepatitis B.

Supported by an agile operating structure, strengthened internal capabilities, and a strong cash position, the Company is well positioned to build a differentiated profile over time through disciplined execution and a long-term strategic perspective.

Full Year 2025 Financial Results 

• Bank deposits and cash and cash equivalents were RMB1,941.0 million as of December 31, 2025, representing a decrease of RMB472.4 million or 19.6% compared with RMB2,413.4 million as of December 31, 2024. The decrease was primarily due to payout of daily operations, research and development activities and acquisition of BRII-179-related assets.
• Revenue was RMB18.6 million for the year ended December 31, 2025, primarily attributable to the upfront payment received under an intellectual property license and technology transfer agreement entered into with Joincare Group.
• Other income was RMB68.8 million for the year ended December 31, 2025, representing a decrease of RMB72.6 million or 51.3% compared with RMB141.4 million for the year ended December 31, 2024. This was mainly due to the decrease in bank interest income of RMB35.6 million attributable to the declining interest rates on USD and HKD time deposits and the RMB33.0 million decrease in recognized income from government grants.
• Research and development expenses were RMB212.9 million for the year ended December 31, 2025, representing a decrease of RMB36.9 million or 14.8% compared with RMB249.8 million for the year ended December 31, 2024. The decrease was primarily attributable to the decrease in third party contracting cost of RMB21.0 million [as the Company continued to prioritize HBV functional cure program, partially offset by increased investment in early discovery programs to support future pipeline growth]. The decrease was also attributable to the decrease in employee cost of RMB16.2 million, mainly resulting from organizational optimization and adjustments to the senior management compensation framework during the Reporting Period.
• Administrative expenses were RMB109.5 million for the year ended December 31, 2025, representing a decrease of RMB43.7 million or 28.5% compared with RMB153.2 million for the year ended December 31, 2024. The decrease was primarily attributable to the decrease in employee cost of RMB24.8 million and professional fees of RMB10.4 million. The decrease was primarily due to organizational optimization, adjustments to the senior management compensation framework and effective cost control during the Reporting Period.
• Loss for the year was RMB224.1 million for the year ended December 31, 2025, representing a decrease of RMB288.3 million or 56.3% compared with RMB512.4 million for the year ended December 31, 2024. The decrease in loss was primarily attributable to a reduction in fair value loss on equity investment of RMB124.5 million and a decrease in impairment losses of RMB141.1 million, which were largely non-operating in nature, as well as lower operating expenses. The decrease in loss was partially offset by the decrease in other income during the Reporting Period.

Conference Call Information

The Company will host two live conference calls. The Chinese session will be held on March 20 at 8:30 a.m. HKT (8:30 p.m. ET on March 19). For the registration link, please click here.  Followed by an English session on March 20 at 8:30 p.m. HKT (8:30 a.m. ET). For the registration link, please click here.

All participants are required to complete the online registration process using the applicable link prior to the conference call. A replay of each of the conference call will be available following the live event and can be accessed by visiting the Company's website at www.briibio.com under the Investor Relations section.

This press release contains references to third-party information. Such information is not deemed to be incorporated by reference in this press release. Brii Bio disclaims responsibility for such third-party information.

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 key biotech hubs, including Raleigh-Durham, the San Francisco Bay Area, Beijing and Shanghai. For more information, visit www.briibio.com.

Forward-Looking Statement

 The information communicated in this press release contains certain statements that are or may be forward-looking. These statements typically contain words such as "will," "expects," "believes," "plans" and "anticipates," and words of similar import. By their nature, forward-looking statements involve risk and uncertainty because they relate to events and depend on circumstances that will occur in the future. There may be additional material risks that are currently not considered to be material or of which the Company is unaware. These forward-looking statements are not a guarantee of future performance. Against the background of these uncertainties, readers should not rely on these forward-looking statements. The Company assumes no responsibility to update forward-looking statements or to adapt them to future events or developments.