Brii Bio Presents New Data at AASLD’s The Liver Meeting® 2023 Highlighting Progress towards a Functional Cure of HBV

Direct evidence that BRII-179-induced functional antibody responses lead to increased and sustained HBsAg loss

New insights into using BRII-179 to enhance patients’ intrinsic humoral immune response to improve HBsAg disappearance or HBV functional cure rate

New data supports entry into late-stage clinical development, data expected to inform treatments for chronic hepatitis B

Durham, North Carolina and Beijing, November 13, 2023 /PRNewswire/ — Brii Biosciences Limited (“Borui Biotechnology” or the “Company”, stock code: 2137.HK), a biotechnology company dedicated to developing therapies to improve patient health and options for diseases with unmet need, today shared three documents at the American Association for the Study of Liver Diseases (AASLD) Poster Liver Conference^® exist Boston, Massachusettstwo of which are considered late-stage breakthroughs, presented new data from two Phase 2 assets BRII-179 (VBI-2601) and BRII-835 (VIR-2218) in chronic hepatitis B (CHB) clinical programs.

“We are pleased to share these data at the Liver Conference, which demonstrate the versatility of our HBV portfolio and the important insights we have in the search for a cure for HBV,” said David MargolisMD, Chief Medical Officer Borui Biotechnology. “The important link between HBsAg loss and antibody responses provides clear direction for further improving functional cure rates and identifying patients most likely to respond to curative treatments. Our goal is to provide the right Developing the right treatment options for the right patient population while sparing patients from expensive or poorly tolerated treatment options that may not be of benefit to them.”

In the latest poster presentation, Borui Biotechnology Announced additional interim data from a cohort-level, randomized, placebo-controlled, double-blind Phase 2 study of BRII-179 in combination with pegylated interferon-alpha (PEG-IFNα) in patients with CHB infection. Blind data. Findings from this presentation include:

• Add-on therapy with BRII-179 to existing PEG-IFNα therapy was generally safe and tolerated, with adverse events similar to those previously reported for PEG-IFNα therapy and BRII-179.
• At week 36 (12 weeks after end of treatment (EOT)), the BRII-179 + PEG-IFNα combination group achieved greater HBsAg disappearance compared with the placebo + PEG-IFNα group (Full Analysis Set (FAS) :24.6% vs. .14.0%, per protocol set (PPS): 31.8% vs. 14.9%). Differences in HBsAg disappearance rates were observed at week 24 (EOT) and maintained through week 36. Clinical studies also found that the HBsAg seroconversion rate in the combination group was significantly higher than that in the placebo + PEG-IFNα group (FAS: 15.8% vs. 1.8) %, p=0.016; PPS: 19.6% 2.0%, p=0.0058) at week 24 (EOT).
• The addition of BRII-179 induced a robust and functional HBsAg antibody response, with participants in the BRII-179 + PEG-IFNα combination group achieving significantly higher HBsAg antibody responses than those in the placebo + PEG-IFNα group at week 24. Hepatitis B surface antibody (HBsAb) response rate (FAS: 38.6% vs. 14.0%, p=0.0052; PPS: 39.1% 13.7%, p=0.0054) and Week 36 (FAS: 33.3% vs. 12.3%, p=0.0131; PPS: 34.1% 10.6%, p=0.0105). HBsAb titer was significantly associated with HBsAg loss at 24 and 36 weeks. No antibody response was detected in 4 of 5 rebound patients.
• Data from this proof-of-concept study demonstrate that adding BRII-179 to induce a functional immune response can improve the rate and duration of HBsAg disappearance in chronic hepatitis B patients treated with PEG-IFNα, thereby improving the rate of functional cure of chronic hepatitis B .

In the second latest poster presentation, Borui Biotechnology Presented translational research data from the BRII-179-001 and BRII-179-835-001 studies demonstrating that the unique HBsAg antibody response induced by BRII-179 was only observed in a subset of CHB subjects, suggesting that some patients have HBV-specific The intrinsic immune response may be more severely compromised. Additionally, the researchers found:

• BRII-179 in combination with BRII-835 (VIR-2218) was generally well tolerated at doses up to 9 months, with no >Grade 2 treatment-related adverse events.
• In participants with chronic hepatitis B receiving nucleos
• Immunological analyzes suggest that BRII-179 may provide a unique opportunity to enrich CHB patients with the ability to elicit the necessary HBsAg antibody responses to achieve higher functional cure rates in some patients while sparing others from unnecessary treat.

In the poster presentation, Borui Biotechnology Highlighting the Multiple-Dose Pharmacokinetics (PK) of BRII-835 (VIR-2218) in Patients with Chronic HBV Infection 1 B

/2 and Phase 2 clinical trials, regional or ethnic background may have an impact on the PK of the drug. Highlights include:

• The PK profile of BRII-835 in patients with chronic HBV infection is generally similar to that in healthy volunteers. A dose-dependent increase in systemic exposure was observed at the 50 and 100 mg doses. There was no significant accumulation in plasma after the second dose was given four weeks later.
• Similar PK profiles among enrolled patients Asia Pacific Regions and continents China Proof of Chinese origin from Mainland China China It has no obvious impact and can be used as a bridge to support the mainland. China’s Participate in future global trials to further evaluate BRII-835.

as part of Borui Biotechnology The company and its partners are conducting multiple ongoing Phase 2 studies, including the combination of BRII-835 and BRII-179, the combination of BRII-179 and PEG-IFN⍺, BRII-835, and BRII-877. (VIR-3434) With or without PEG-IFN⍺. Additionally, Vir Biotechnology, Inc. (“Vir”) is investigating VIR-2218 and/or VIR-3434 for the treatment of HBV/HDV coinfections.

About hepatitis B
Hepatitis B virus infection is one of the world’s most serious infectious disease threats, with more than 290 million people infected globally.¹ Chronic HBV infection is a major cause of liver disease, and an estimated 820,000 people die from complications of chronic HBV each year.¹ Hepatitis B virus (HBV) receives special attention China87 million people were infected.²

About BRII-179
BRII-179 (VBI-2601) is a novel HBV immunotherapy candidate based on recombinant proteins expressing Pre-S1, Pre-S2 and S HBV surface antigens designed to induce enhanced and broad B-cell and T-cell immunity. BRII-179 is currently being studied in two Phase 2 clinical trials in combination with BRII-835 or PEG-IFNα as part of a potential functional cure regimen for the treatment of chronic HBV infection.

Borui Biotechnology BRII-179 Licensed from VBI Vaccines, Inc. (“VBI”) December 2018,supply Borui Biotechnology Commercial rights to BRII-179 are licensed in the following countries: China, Hongkong, Macaoand Taiwan. Exclusive license for BRII-179 expanded to global markets July 2023.

About BRII-835
BRII-835 (VIR-2218) is an investigational subcutaneously administered HBV-targeting siRNA that has the potential to stimulate an effective immune response and have direct antiviral activity against HBV. It is the first siRNA in the clinic to employ enhanced stability chemical enhancement (ESC+) technology to enhance stability and minimize off-target activity, which may result in an increased therapeutic index. Borui Biotechnology Receives exclusive rights to develop and commercialize BRII-835 on a larger scale China Acquired territory from Vir Biotechnology, Inc. (“Vir”) in 2020.

About BRII-877
BRII-877 (VIR-3434) is an investigational, subcutaneously administered HBV-neutralizing monoclonal antibody designed to block the entry of all 10 genotypes of HBV into hepatocytes and reduce blood levels of virions and subviral particles. BRII-877 (VIR-3434) combines Xencor’s Xtend™ and other Fc technologies and is engineered as a T-cell vaccine against HBV in infected patients with an extended half-life. Borui Biotechnology Receives exclusive rights to develop and commercialize BRII-877 on a larger scale China 2022 Seize territory from Vir Biotechnology, Inc. (“Vir”).

about Borui Biotechnology
Borui Biotechnology Co., Ltd. (“Borui Biotechnology“, stock code: 2137.HK) is a commercial-stage biotechnology company developing treatments to address major public health challenges where patients face high unmet medical needs, limited options and severe social stigma. The company focuses on The company is advancing a pipeline of unique therapeutic candidates for infectious diseases and central nervous system diseases, including lead programs targeting hepatitis B virus infection (HBV), postpartum depression (PPD) and major depressive disorder (MDD). The company is led by a visionary and experienced leadership team and has operations in major biotechnology centers, including Raleigh-Durhamthis san francisco bay area, Beijing and Shanghai. For more information, please visit www.briibio.com.

1 World Health Organization. (June 2022). Hepatitis B. World Health Organization. Retrieved from https://www.who.int/news-room/fact-sheets/detail/hepatitis-b
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.

SOURCE Brii Biosciences Limited