Brii Bio Doses First Patient in Phase 2a/2b Clinical Trial of BRII-179 (VBI-2601) for the Functional Cure of Chronic Hepatitis B

Brii Biosciences Limited ("Brii Bio" or the "Company", stock code: 2137.HK) a multi-national company developing innovative therapies for diseases with significant unmet medical needs and large public health burdens, has dosed the first patient in a Phase 2a/2b clinical trial for BRII-179 (VBI-2601) in patients with chronic hepatitis B virus (HBV). An estimated 290 million people worldwide are living with chronic HBV infection, and nearly 800,000 people die each year[1] from complications such as HBV-related cirrhosis, liver failure, and related cancers.

"BRII-179 has the potential to break immune tolerance and restore or augment adaptive T cell and antibody responses to HBV surface antigens. This would establish a durable immune response to HBV and create the possibility of achieving a functional cure for chronic HBV infection," said Li Yan, MD, Ph.D., chief medical officer at Brii Bio. "Chronic HBV patients currently only have access to treatments that result in a single-digit functional cure rate. We look forward to working with our investigators in China to determine the safety and impact of BRII-179 in reinvigorating HBV-specific adaptive immune function in this patient population, which could potentially translate into a significantly higher functional cure rate."

BRII-179 (VBI-2601) is a novel recombinant, protein-based HBV immunotherapeutic candidate that expresses the Pre-S1, Pre-S2, and S HBV surface antigens, and is designed to induce enhanced B-cell and T-cell immunity. BRII-179 (VBI-2601) builds upon the 3-antigen conformation of VBI Vaccines' prophylactic HBV vaccine, which is approved in the U.S. under the name PreHevbrio™ [Hepatitis B Vaccine (Recombinant)].

This Phase 2 trial of BRII-179 is a double-blind, randomized, placebo-controlled, parallel-group study to evaluate the clinical effect of adding BRII-179 (VBI-2601) to existing PEG-IFN-α and nucleos(t)ide reverse transcriptase inhibitor (NrtI) standard-of-care therapy in non-cirrhotic chronic HBV patients. Patients participating in the study have met a pre-defined criteria for partial responses to ongoing PEG-IFN-α and NrtI treatment. An independent Data and Safety Monitoring Board will monitor patient safety and treatment efficacy data for this study.

Phase 2a:

• The Phase 2a part of the study will determine the efficacy and safety of BRII-179 (VBI-2601) therapy in approximately 120 patients in combination with PEG-IFN-α + Nrtl therapy.

• The primary endpoint of Phase 2a is the percentage of patients with HBsAg loss at the completion of treatment.

Phase 2b:

• In Phase 2b, the study will expand to 480 patients to evaluate the proportion of patients achieving functional cure after receiving BRII-179 (VBI-2601) therapy in combination with PEG-IFN-α + NrtI.

• The primary endpoint of Phase 2b is the percentage of patients achieving sustained HBsAg and HBV DNA loss.

For more information about Brii Bio and its clinical pipeline, visit www.BriiBio.com.

About Hepatitis B

Hepatitis B is one of the world's most significant infectious disease threats, with more than 290 million people infected globally. HBV infection is the leading cause of liver disease, and, with current treatments, it is very difficult to cure, and many patients go on to develop liver cancers. An estimated 780,000 people die each year from complications of chronic HBV, such as liver decompensation and hepatocellular carcinoma.

About BRII-179 (VBI-2601)

BRII-179 (VBI-2601) is a novel recombinant, protein-based HBV immunotherapeutic candidate that expresses the Pre-S1, Pre-S2, and S HBV surface antigens, and is designed to induce enhanced B-cell and T-cell immunity. Brii Bio licensed BRII-179 (VBI-2601) from VBI Vaccines in December of 2018, providing Brii Bio with commercial rights to BRII-179 (VBI-2601) in the licensed territories of Mainland China,  Hong Kong, S.A.R., China, Macau, S.A.R., China,S.A.R.,China, and Taiwan, China,China.

In addition to this Phase 2 trial, BRII-179 (VBI-2601) is also currently being investigated in Phase 2 combination study with different agents as part of potential functional cure regimens for the treatment of chronic HBV infection.

About Brii Bio

Brii Biosciences Limited ("Brii Bio", or the "Company", stock code: 2137.HK) is a biotechnology company based in China and the United States committed to advancing therapies for significant infectious diseases, such as hepatitis B, COVID-19, human immunodeficiency virus (HIV) infection, multi-drug resistant (MDR) or extensive drug resistant (XDR) gram-negative infections, and other illnesses, such as the central nervous system (CNS) diseases, which have significant public health burdens in China and worldwide. For more information, visit www.briibio.com.

[1] Stanaway JD, et al. The global burden of viral hepatitis from 1990 to 2013: findings from the Global Burden of Disease Study 2013. Lancet 2016; 388(10049): 1081-1088.

Source: Brii Biosciences Limited