Brii Biosciences Announces First Subject Dosed in Phase 1 Clinical Trial of BRII-297, Long-Acting Injectable for the Treatment of Anxiety and Depressive Disorders

BRII-297,a first-of-its-kind treatment option for anxiety and depressive disorders,has the potential to enable greater therapeutic adherence and convenience for patients

DURHAM,N.C. and BEIJING,June 1,2023 --Brii Biosciences Limited ("Brii Bio" or the "Company",stock code: 2137.HK),a biotechnology company developing therapies to improve patient health and choice across diseases with high unmet need,today announced the first subject has been dosed in a Phase 1 clinical trial evaluating BRII-297,a first-of-its-kind long-acting injectable (LAI),in development for the treatment of various anxiety and depressive disorders. This Phase 1 study is examining the safety,tolerability and pharmacokinetics of BRII-297 in healthy volunteers in Australia.

"We are eager to continue advancing BRII-297 through the Phase 1 clinical trial and evaluate the potential of our long-acting technology to provide a differentiated treatment option for patients as they navigate their mental health journeys," said Lianhong Xu,Ph.D.,Head of Discovery at Brii Bio. "We believe psychiatric conditions such as anxiety and depressive disorders require treatment options that take into consideration of patient insights and preferences,so that patients can get the care they need in a timely and convenient way. Through our in-house discovery,we are thoughtfully designing BRII-297 and other long-acting therapies across our pipeline with the aim of improving outcomes and eliminating social stigma."

BRII-297 is a new chemical entity (NCE) discovered internally. It acts as a novel gamma-aminobutyric acid A (GABAA) receptor positive allosteric modulator (PAM) with a LAI formulation,designed to provide rapid,profound and sustained reduction of symptoms,which has the potential to enable therapeutic adherence and convenience for patients living with anxiety and depressive disorders.

About Anxiety and Depressive Disorders

In 2019,nearly one billion people were living with a mental health disorder. Since the emergence of the COVID-19 pandemic,anxiety and depressive disorders have increased by a staggering 25%. Despite the high prevalence of mental health conditions and scientific innovations that have opened the door to developing more effective therapeutics,social stigma and discrimination remain significant barriers to accessing and receiving care for psychiatric conditions.

About BRII-297

BRII-297 is a first-of-its-kind long-acting injectable (LAI) therapeutic candidate in development for the treatment of various anxiety and depressive disorders. Discovered internally,BRII-297 acts as a gamma-aminobutyric acid A (GABAA) receptor positive allosteric modulator (PAM),a proven mechanism of action that is known to potentially restore "normal" levels GABAA receptor function for various depressive and anxiety central nervous system disorders.

About Brii Bio

Brii Biosciences 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.