Brii Biosciences Broadens its Leadership in Hepatitis B with a Portfolio Now Addressing Disease's Burdens from Prevention to Cure

Extension of BRII-179 license from VBI Vaccines to global rights bolsters Brii Bio's position to achieve best-in-class HBV functional cure in broad patient populations

Company also acquires exclusive rights to PreHevbri®,a clinically differentiated,3-antigen prophylactic vaccine,from VBI in Greater China and Asia Pacific markets

Company to host conference call on July 6 at 8:30 AM (HKT) / July 5 at 8:30 PM (EST)

BEIJING and DURHAM,N.C.,July 6,2023 -- Brii Biosciences Limited ("Brii Bio," "we," or the "Company",stock code: 2137.HK),a biotechnology company developing therapies to improve patient health and choice across diseases with high unmet needs,today announced that it has entered into license agreements with VBI Vaccines,Inc. ("VBI",NASDAQ: VBIV),expanding the companies' collaboration in the hepatitis B virus (HBV) field.

The newly formed license agreements with VBI signify a substantial expansion in the fight against HBV infection. In the first agreement,Brii Bio's exclusive license for BRII-179 (VBI-2601) is extended to worldwide markets,further establishing its leadership position in pursuing HBV functional cure. A growing body of evidence supports the importance of a strong HBV-specific immune response to achieve a durable HBV functional cure,highlighting a potentially important role for BRII-179 as part of a combination cure strategy.

Additionally,Brii Bio will acquire exclusive rights to develop and commercialize PreHevbri® in Greater China and Asia Pacific countries including Australia,Indonesia,Malaysia,New Zealand,Philippines,Singapore,South Korea,Thailand and Vietnam,among others. PreHevbri® is a clinically differentiated 3-antigen adult HBV prophylactic vaccine recently approved for use in the United States,European Union/European Economic Area,United Kingdom,Canada,and Israel. Under the terms of the agreements,VBI will receive upfront payments of $15 million including $5 million ring-fenced for manufacturing and supply as well as $3 million equity investment by Brii Bio,contingent on achievement of near-term milestones. VBI is also eligible to receive additional payments based on achievement of regulatory and commercial milestones,as well as royalties. The transaction is subject to certain closing conditions including the satisfactory completion of VBI's financing.

"We are excited to substantially strengthen our partnership with VBI,expanding our HBV pipeline and reinforcing our commitment to public health by combatting HBV," said Zhi Hong,Ph.D.,Chairman and Chief Executive Officer of Brii Bio. "By exploring the combination cure strategies across our portfolio,we aim to produce the most durable curative treatment in the broadest populations of HBV patients. The addition of PreHevbri®,VBI's prophylactic vaccine,to our HBV portfolio allows us to address HBV burdens from prevention to cure and jump-start our commercialization efforts in China and Asia Pacific with high HBV prevalence and population density,unlocking significant revenue potential."

BRII-179 (VBI-2601) is currently undergoing Phase 2 studies led by Brii Bio in China,evaluating its potential as a key component of a functional cure for chronic HBV patients. Promising results from multiple studies,including Vir Biotechnology's MARCH study and Brii Bio's ongoing Phase 2 trials combining BRII-179 (VBI-2601) with BRII-835 (VIR-2218),have shown a strong correlation between durable HBsAg seroclearance and antibody seroconversion,highlighting the potential of BRII-179 (VBI-2601) as a valuable immunomodulatory component within a functional cure regimen. Brii Bio intends to further evaluate BRII-179 as part of a combination cure strategy in upcoming studies,with a goal to substantially improve upon cure rates achieved with PEG-IFN-α alone and to expand the population of chronic HBV patients eligible for a potential cure.

PreHevbri®,also known as PreHevbrio® in the U.S. and Canada,PreHevbri® in the European Union/European Economic Area and United Kingdom,and Sci-B-Vac® in Israel,is the only approved 3-antigen HBV vaccine. In pivotal Phase 3 clinical studies,PROTECT and CONSTANT,PreHevbri®showed higher rates of and long-lasting seroprotection across all subjects aged 18+,and 5 to 8 times higher antibody titers compared to Engerix-B,a single-antigen HBV vaccine. Moreover,an integrated safety analysis of both studies demonstrated that PreHevbri® is well tolerated with no unexpected reactogenicity observed.

Conference Call Information

A live conference call will be hosted on Thursday,July 6 at 8:30 AM Hong Kong time (Wednesday,July 5 at 8:30 PM U.S. Eastern Time). All participants are required to register in advance of the call. For the registrationlink,please click here.

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-179 (VBI-2601) is currently being investigated in two Phase 2 clinical trials in combination with BRII-835 (VIR-2218) and PEG-IFN-α as part of a potential functional cure regimen for the treatment of chronic HBV infection.

About PreHevbri®

PreHevbri®is the only 3-antigen hepatitis B vaccine,comprised of the three hepatitis B surface antigens of the hepatitis B virus – S,pre-S1,and pre-S2. It is approved for use in the United States,and Israel. The brand names for this vaccine are: PreHevbrio® (US/Canada),PreHevbri®(EU/EEA/UK),and Sci-B-Vac® (Israel).

About Hepatitis B

Hepatitis B viral infection (HBV) is one of the world's most significant infectious disease threats with more than 290 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 each year.1 HBV is of exceptional concern in China,where 87 million people are infected.2

About Brii Bio

Brii Biosciences ("Brii Bio",stock code: 2137.HK) is a biotechnology company developing therapies to address some of the world's most common diseases where patients experience high unmet medical needs,limited choice and significant social stigmas. With a focus on infectious and central nervous system diseases,the Company is advancing a broad pipeline of unique therapeutic candidates with lead programs to develop a novel functional cure for hepatitis B viral infection (HBV) and first-of-its-kind treatment options for postpartum depression (PPD) and major depressive disorder (MDD). 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.

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

2World 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.