- Company received US FDA clearance of Investigational New Drug Applications for four diverse pipeline candidates and advanced each into the clinic

DURHAM, N.C., United States and BEIJING, China – May 17, 2021 – Brii Biosciences (“Brii Bio”), a multi-national
company developing innovative therapies for diseases with significant unmet medical needs and large
public health burden, today provided an update on clinical development progress across its broad
pipeline of investigational therapies. The Company has advanced eight therapeutic candidates across
various stages of clinical development, addressing some of the world’s biggest public health issues
and disease burdens in areas such as HIV infection, postpartum depression (PPD), multi-drug
resistant (MDR) gram-negative bacterial infections, COVID-19 and hepatitis-B (HBV).

“In the five months since our last corporate update, we have made significant progress advancing
clinical development of the various therapeutic candidates across our broad pipeline. In addition to
ushering four new investigational therapies into clinical development, we recently announced
continuation of BRII-196 and BRII-198 into a global Phase 3 trial for COVID-19, as well as progress
in the BRII-835 and BRII-179 combination Phase 2 multi-regional clinical trial for chronic HBV
infection,” said Zhi Hong, Ph.D., CEO of Brii Bio. “We look forward to building on this momentum as
we advance our innovative programs through clinical development and continue to grow our company,
tackling diseases that present major global public health challenges and acquiring promising
clinical candidates through our existing collaborations.”

HIV Updates

  • Under an approved U.S. Investigational New Drug Application (IND), Brii Bio has dosed subjects
    in the first cohort of its Phase 1 clinical trial evaluating BRII-732, a therapeutic designed for
    once-weekly oral dosing with potential to improve the quality of life of HIV-infected patients.
    Top-line results are expected in the first quarter of 2022.
  • In March, the Company also initiated, under an approved U.S. IND, its Phase 1 clinical trial
    with BRII-778, another therapeutic designed for once-weekly oral dosing for HIV-infected patients.
    Top-line results are expected by the end of 2021.

Central Nervous System Disease (CNS) Updates

  • Following approval of a U.S. IND, Brii Bio began dosing patients in April 2021 in its Phase 1
    clinical trial with BRII-296 for the treatment of PPD.
  • BRII-296 is being developed for PPD as well as major depressive disorder (MDD) and has potential
    to change the paradigm of patient care, helping to avoid hospitalization, preserve mother-infant
    bonding in PPD, and improve the safety and tolerability of current therapies. Top-line results are
    expected by the end of 2021.

Multi-drug Resistant (MDR) Gram-Negative Bacterial Infections Updates

  • Brii Bio and its licensing partner, Qpex Biopharma (USA), are developing three products, two of
    which are based on the ultra-broad spectrum beta-lactamase inhibitor QPX7728, as part of the fixed
    combination products BRII-636 (OMNIvance®) IV and
    (ORAvance™) oral.
  • Qpex recently initiated a Phase 1 study under an approved U.S. IND
    evaluating BRII-672 (ORAvance™), an oral ultra-broad-spectrum beta-lactamase inhibitor
    for the
    treatment of extended spectrum beta-lactamase (ESBL) and/or carbapenemase producing
    Enterobacteriaceae. Top-line results are expected in the first half of 2023.
  • Qpex continues to develop BRII-636 (OMNIvance®)
    under an
    approved U.S. IND in a Phase 1 study of
    single and multiple ascending doses, which will include a cohort of first- or second-generation
    Chinese subjects in the second half of 2021. Top-line results are expected in the first half of
  • Qpex is also proceeding with its planned Phase 1 study under an approved U.S. IND for BRII-693
    (QPX-9003), a next generation synthetic polymyxin for the treatment of MDR infections caused by
    Pseudomonas aeruginosa and Acinetobacter baumannii. Dosing for this trial is planned
    to commence by the end of this quarter. Top-line results are expected in the first half of 2022.
  • Brii Bio and Qpex previously entered into a strategic collaboration to develop and commercialize
    three of Qpex’s investigational products to treat a range of MDR gram-negative infections in
    Greater China. Under the terms of that agreement, Brii Bio obtained a license to develop,
    manufacture, and commercialize these products in Greater China, and Qpex retained all other rights

SARS-CoV-2 Updates

  • Brii Bio announced on April 29 that its monoclonal antibody combination therapy,
    BRII-196 and BRII-198, have been transitioned to Phase 3 of the ACTIV-2 trial in ambulatory
    COVID-19 patients with high risks for disease progression based on the recommendation of a Data
    Safety Monitoring Board composed of independent subject matter experts following a Phase 2
    pre-specified analysis for safety and efficacy.
  • The Phase 3 portion of the study, which has been actively enrolling participants, is expanding
    into international trial sites, allowing for a broader assessment of the BRII-196 and BRII-198
    combination against emerging variants in ambulatory COVID-19 patients.

Hepatitis-B (HBV) Cure Updates

  • Brii Bio, along with its licensing partners, Vir Biotechnology and VBI Vaccines, announced on April 21 that the first patient was dosed in a Phase 2
    clinical trial evaluating BRII-835 (VIR-2218) in combination with BRII-179 (VBI-2601) for the
    treatment of chronic HBV infection.
  • The multi-center, randomized, open-label study is designed to evaluate the safety and efficacy
    of BRII-835 compared to the combination of BRII-835 and BRII-179 with and without low dose
    interferon-alpha as a co-adjuvant and will be conducted at sites in Australia, China, Taiwan, Hong
    Kong Special Administrative Region of China, South Korea, New Zealand, Singapore, and Thailand.
  • The Company has exclusive rights to develop and commercialize BRII-179 and BRII-835 in Greater
    China, while VBI and Vir have the exclusive rights to BRII-179 and BRII-835, respectively, in the
    rest of the world.

About Brii Biosciences
Brii Biosciences is a multi-national company committed to serving patients' needs and improving
public health by accelerating the development and delivery of breakthrough medicines through
partnerships, best-in-class research and development, and the disruptive application of digital and
data insight. With operations in the People's Republic of China and the United States, Brii Bio is
poised to serve as a bridge to carry transformative medicines to patients, help create significant
growth for our partners and establish an innovation engine to help improve the public health and
wellbeing of patients around the world. Brii Bio is developing treatments for illnesses with
significant public health burdens, including infectious diseases and CNS diseases. For more
information, visit www.briibio.com.