Brii Biosciences Announces Entry into Definitive Agreements from Sale of its Equity Interest in Qpex Biopharma and Acquiring Exclusive Global Rights for BRII-693

Company acquires exclusive global rights of the novellipopeptide BRII-693 for the difficult to treat MDR/XDR gram-negative bacterial infections

Company returns Greater China rights toQpex Biopharma of beta-lactamase inhibitor QPX7728-based products

Company to receive ~$24M upfront cash payments

DURHAM,N.C. and BEIJING,June 25,2023 -- 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 entered into definitive agreements with Qpex Biopharma ("Qpex") and third parties in connection with the acquisition of Qpex by Shionogi.

Under the terms of the agreement,Brii Bio will acquire exclusive global rights for the development and commercialization of BRII-693 (also known as QPX9003) to expand from its existing rights in Greater China. All existing cost-share,milestone and royalty payments associated with BRII-693 to Qpex are eliminated. The Company will return its exclusive rights to QPX7728-based products BRII-636 and BRII-672 in Greater China to Qpex and Brii will no longer be responsible for cost-share,milestone and royalty payments to Qpex associated with these products.

In association with the return of QPX7728-based program rights to Qpex,Qpex will complete a merger through acquisition by Shionogi. Brii Bio will receive approximately $24 million upon closing of the acquisition as a Qpex shareholder and the return of the QPX7728 product rights,with potential contingency payments for future milestone events in the US.

BRII-693 is a novel synthetic lipopeptide in development for the treatment of critically ill patients with MDR/XDR gram-negative bacterial infections,especially carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa. In October 2019,Brii Bio entered into a licensing agreement with Qpex to develop and commercialize BRII-693 and the QPX7728-based products in Greater China.

"With the demonstrated antibacterial mechanism and improved safety profile,BRII-693 has the potential to be the safest and most effective polymyxin for the treatment of critically ill patients with gram-negative bacterial infections," said Zhi Hong,Ph.D.,Chairman and Chief Executive Officer of Brii Bio,"Given the microbiological and clinical profile of BRII-693,we are very excited about this opportunity to prioritize and focus on the global development of this agent."

In April 2023,Brii Bio submitted a pre-IND to the National Medical Products Administration (NMPA) for the development of BRII-693 (QPX9003) in China.

About BRII-693

BRII-693 is a novel lipopeptide antimicrobial that was discovered under the directions of Professor Jian Li of the Biomedicine Drug Discovery Institute of Monash University in Australia. BRII-693's discovery was supported in part by funds from the U.S. National Institutes of Allergy and Infectious Diseases (NIAID; RO1 AI098771 and AI132154). The discovery of BRII-693 and preclinical studies were described in 2022 in the journal Nature Communications and show improved potency and less toxicity compared to older polymyxin antimicrobial agents. BRII-693 has the potential to be an important advance in the treatment of gram-negative infections,including MDR/XDR strains,with improved renal safety compared to currently available polymyxin antibiotics.

In 2021,the US FDA designated QPX-9003 (BRII-693) to be a Qualified Infectious Disease Product (QIDP). The QIDP designation provides incentives for the development of BRII-693 in the US,including priority review and eligibility for FDA'sFast Track Designation; there is also the potential for extension of regulatory and market exclusivity in the US.

In October 2022,the interim Phase 1 results from a completed first-in-human clinical study conducted in the US presented at ID Week in Washington DC demonstrated that BRII-693 is safe and well-tolerated at all doses tested. An end of Phase 1 meeting was convened with the US FDA in December 2022 and these results along with approaches for a future Phase 3 program were discussed with the agency.

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 a first-of-its-kind treatment for postpartum depression (PPD). 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.