Brii Bio Announces Strategic Partnership with Sinopharm to Advance Commercialization of Long-Acting COVID-19 Neutralizing Antibody Therapy, Amubarvimab/Romlusevimab Combination, in China

DURHAM,N.C. and BEIJING,March 30,2022 --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,today announced that TSB Therapeutics (Beijing) Co.,Ltd. ("TSB Therapeutics"),a joint venture majority-owned by the Company,is partnering with Sinopharm Holding Co.,Ltd. ("Sinopharm Holding")to advance stockpiling,channel distribution and regional access of the Company's long-acting neutralizing monoclonal antibody (mAb) therapy,the amubarvimab/romlusevimab combination,to help contribute to COVID-19 pandemic prevention and control efforts in China.

On December 8,2021,the National Medical Products Administration (NMPA) of China approved the amubarvimab/romlusevimab combination (previouslyBRII-196/BRII-198 combination) for the treatment in adults and pediatric patients (age 12-17 weighing at least 40 kg) with mild and normal type of COVID-19 at high risk for progression to severe disease,including hospitalization or death. The indication of pediatric patients (age 12-17 weighing at least 40 kg) is under a conditional approval. On March 15,2022,the National Health Commission of China added the amubarvimab/romlusevimab combination to its COVID-19 Diagnosis and Treatment Guidelines (9th Pilot Edition) ("Guidelines") for the treatment of COVID-19.

"The pandemic continues to affect the health of communities worldwide and most recently aggressively impacting China. As a biotechnology company with the mission of tackling the major public health challenges,we are duty-bound to support the pandemic prevention and control," said Rogers Luo,President and General Manager,Greater China of Brii Bio,and Chief Executive Officer of TSB Therapeutics. "We are pleased to partner with Sinopharm Holding,a leading state-owned pharmaceutical distribution company in China. We believe that with their advanced distribution channels and strong channel management ability,we are able to accelerate the accessibility of our amubarvimab/romlusevimab combination to help more COVID-19 patients in China."

"It has been three years since the outbreak of the pandemic. We have been expecting treatment solutions to be available in addition to the COVID-19 vaccines,"said Yong Liu,President and Deputy Secretary of the Party Committee of Sinopharm Holding. "As a central pharmaceutical stockpiling company,Sinopharm Holding is committed to ensuring the drug supply for our country and people. The strategic partnership with Brii Bio marks essential public health cooperation between a commercial enterprise and an industrial enterprise. We will leverage our strong distribution network in cooperation with our provincial subsidiaries and our global procurement and supply chain centers,to provide a comprehensive strategy,including drug stockpiling,commercialization,and innovation services,thereby improving the accessibility of Brii Bio's self-developed COVID-19 antibody therapy and benefiting more patients."

On March 21,the National Healthcare Security Administration of China issued a notice to temporarily include the newly added drugs in the Guidelines in reimbursement by the provincial health insurance fund. Since March 22,the Healthcare Security Administrations of various provinces and cities,including Hunan,Beijing,Shanghai,Zhejiang,Jiangsu,Sichuan,Shanxi,Guizhou,Liaoning and Anhui,have successively implemented the instructions of the notice and included the amubarvimab/romlusevimab combination into the reimbursement of the local health insurance fund.

With the recognition of the national healthcare authorities and clinical experts for the amubarvimab/romlusevimab combination,as of March 29,TSB Therapeutics has received purchase intention and stockpiling requests from nearly20 provincial Health Commissions,over 100 healthcare institutions and commercial organizations. The Company is rapidly preparing production and supply to provide the combination therapy to patients in need as soon as possible.

About Amubarvimab/Romlusevimab Combination

Amubarvimab and Romlusevimab are non-competing SARS-CoV-2 monoclonal neutralizing antibodies derived from convalesced COVID-19 patients developed in collaboration with the 3rd People's Hospital of Shenzhen and Tsinghua University. They have been specifically engineered to reduce the risk of antibody-dependent enhancement and prolong the plasma half-lives for potentially more durable treatment effect.

Based on the final results from the U.S. National Institutes of Health (NIH)-sponsored ACTIV-2 Phase 3 clinical trial with 837 enrolled outpatients,the amubarvimab/romlusevimab combination demonstrates a statistically significant 80% reduction of hospitalization and death with fewer deaths through 28 days in the treatment arm (0) relative to placebo (9),and improved safety outcome over placebo in non-hospitalized COVID-19 patients at high risk of clinical progression to severe disease. Similar efficacy rates were observed in participants initiating therapy early (0-5 days) and late (6-10 days),following symptom onset,providing critically needed clinical evidence in COVID-19 patients who were late for treatment.

The in vitro pseudovirus testing data from independent labs demonstrates that the amubarvimab/romlusevimab combination retains activity against the emerging SARS-CoV-2 variant B.1.1.529 (Omicron) and other major variants of concern,including B.1.1.7 (Alpha),B.1.351 (Beta),B.1.617.2 (Delta),AY.4.2 (Delta Plus),B.1.429 (Epsilon),P.1 (Gamma),C.37 (Lambda) and B.1.621 (Mu).

In October 2021,the Company initiated and subsequently completed the rolling submission of an emergency use authorization (EUA) application with the U.S. Food and Drug Administration. In addition,the Company is pursuing additional efforts and regulatory filings for the amubarvimab/romlusevimab combination in established and emerging markets with an initial focus on securing access in countries where clinical trials were conducted and where significant gaps in access to highly effective treatments have been identified. The Company is planning further studies in China,to evaluate the use of the amubarvimab/romlusevimab combination among immunocompromised population as an additional measure of prophylaxis.

About Brii Bio

Brii Biosciences Limited ("Brii Bio",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.

About TSB Therapeutics

TSB Therapeutics (Beijing) Co.,Ltd. ("TSB Therapeutics",or the "Company") is a holding company of Brii Bio. TSB Therapeutics was jointly established in Beijing in May 2020 by Brii Bio,the 3rd People's Hospital of Shenzhen and Tsinghua University. The Company is committed to developing the amubarvimab/romlusevimab combination. TSB Therapeutics holds exclusive rights to develop and commercialize the amubarvimab/romlusevimab combination in Greater China.

About Sinopharm Holding

Sinopharm Holding Co.,Ltd. ("Sinopharm Holding",01099.HK) was established in Shanghai in January 2003 and listed in Hong Kong in September 2009. It has now become the largest distributor and retailer of drugs,healthcare products and medical devices,as well as a leading supply chain service provider in China. Its parent company China National Pharmaceutical Group Corporation ("CNPGC") ranked 109 in the 2021 Fortune Global 500 and Sinopharm Holding ranked 22nd in the 2021 Fortune China 500. In 2021,Sinopharm Holding recorded a business revenue of RMB 521.051 billion,a year-on-year increase of 14.16%. For the drug distribution segment,Sinopharm Holding firmly grasped the industry transformation trend brought about by volume based procurement ("VBP") policy,and promoted the transformation of drug distribution to nationalized and intensive services by continuously tapping the scale advantage of its distribution network. By the end of 2021,the revenue of its drug distribution segment totaled RMB 389.955 billion,indicating a year-on-year increase of 11.96%,and the distribution network already covered more than 500,000 terminals in various provinces (autonomous regions and municipalities). Sinopharm Holding,firmly taken "All for Health,Health for All" as its corporate mission,has been becoming an excellent global pharmaceutical and healthcare service provider to fully serve the "Healthy China " strategy and actively fulfill its social responsibilities as a central healthcare enterprise.