February 24, 2022
SymBio Pharmaceuticals Limited
Fuminori Yoshida
Representative Director
President and Chief Executive Officer(Securities Code: 4582)

SymBio announces results of a collaborative study with the National Institute of Infectious
Diseases on adenoviruses and the antiviral agent brincidofovir
TOKYO, Japan, February 24, 2022 -- SymBio Pharmaceuticals Limited (Headquarters: Tokyo,"SymBio") today announced that it has published the results of ongoing joint research with the National
Institute of Infectious Diseases on the antiviral drug brincidofovir (“BCV”).
In April 2020, Dr. Nozomu Hanaoka, the Fourth Laboratory of Center for Emergency Preparedness andResponse, the National Institute of Infectious Diseases (Department of Pathogenesis Diagnosis: Headof Department Dr. Tsuguto Fujimoto), and SymBio initiated this joint study to verify the antiviral
activity of BCV against 17 serotypes of adenovirus, including serotypes of unknown responsiveness.
The research showed BCV to exhibit a high level of antiviral activity, particularly against D54 or B11,
which are known in Japan to cause hemorrhagic cystitis after epidemic keratoconjunctivitis or
hematopoietic stem-cell transplantation. Based on these findings, articles were published in thescientific journal, Microbiology Spectrum. See note below for further detail on the published articles.
Dr. Nozomu Hanaoka's research group conducts research on the isolation, identification, and analysisof viruses and microorganisms responsible for a variety of infectious diseases occurring in Japan, andis one of the leading research facilities on adenovirus in the world. In this collaborative study, we wereable to verify the activity of BCV in various adenovirus serotypes as a basis for further development ofBCV as a therapeutic agent.
Statement from Mr. Fuminori Yoshida, President and Chief Executive Officer of SymBio: "There is nopreviously approved antiviral drug for adenovirus, and there is a high medical need. The results of thisjoint research suggest the potential of BCV not only for adenovirus infection in children after
hematopoietic stem cell transplantation and organ transplantation, which are under development, butalso for related diseases, including ophthalmology."[Contact]
Investor Relations
Tel: +81 (0)3 5472 1125

1About Anti-viral Drug Brincidofovir
Brincidofovir (BCV) is a lipid conjugate of cidofovir (CDV). CDV is an antiviral drug already approved
and marketed in the United States and the European Union, but unapproved in Japan. As BCVexhibits not only higher anti-viral activity, but also a superior safety profile in comparison with CDV,
BCV is expected to be an effective treatment against a wide spectrum of dsDNA viruses such as
herpesviruses such as cytomegalovirus (CMV), adenovirus (AdV), Epstein-Barr virus (EBV) and BKvirus, papillomavirus. Moreover, BCV is an easy-to-use and novel highly active antimultiviral agent
that can reduce the risk of nephrotoxicity, which is a serious side effect of CDV.
SymBio entered into an exclusive global license agreement with Chimerix Inc. (Headquarters:Durham, NC, "Chimerix") for brincidofovir (BCV) on September 30, 2019. Under the terms of theagreement, Chimerix grants SymBio exclusive worldwide rights to develop, manufacture, andcommercialize BCV in all human indications, excluding the prevention and treatment of orthopox
infections (which includes smallpox and monkeypox).
Summary of the Published Articles
Sensitivity of Human Mastadenovirus, the Causal Agent of Pharyngoconjunctival Fever, Epidemic
Keratoconjunctivitis, and Hemorrhagic Cystitis in Immunocompromised Individuals, to Brincidofovir
Seventeen different serotype adenoviruses were infected with cultured cells, and half-maximal
inhibitory concentration (IC50) were obtained from the response in which different levels of BCV wereadded to inhibit replication in a test system in which replication of each viral genomic DNA wasdetermined by quantitative PCR. D54, which is responsible for epidemic keratoconjunctivitis in thecountry, was the most susceptible (IC50=1 nM) and also showed excellent antiviral activity (IC50=2-7nM) against other types. On average, it showed 200-fold stronger activity than cidofovir examined asa comparator.
The journal Microbiology Spectrum is one of the scientific journals (peer-reviewed scientific journal)
with review of articles published by the American Society for Microbiology that can be accessed fromthe following URLs.
https://pubmed.ncbi.nlm.nih.gov/35171015/
About SymBio Pharmaceuticals Limited
SymBio Pharmaceuticals Limited was established in March, 2005 by Fuminori Yoshida who
previously served concurrently as Corporate VP of Amgen Inc. and founding President of Amgen
Japan. In May, 2016 the Company incorporated its wholly-owned subsidiary in the U.S., called
SymBio Pharma USA, Inc. (Headquarters: Durham, North Carolina, President: Mr. FuminoriYoshida).
The Company’s underlying corporate mission is to “deliver hope to patients in need” as it
aspires to be a leading global specialty biopharmaceutical company dedicated to addressing
underserved medical needs.

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