September 8, 2021
SymBio Pharmaceuticals LimitedFuminori Yoshida
Representative Director
President and Chief Executive Officer(Securities Code: 4582)

SymBio announces initiation of non-clinical study of brincidofovir IVat the Brain Tumor Center, Department of Neurological Surgery
University of California, San Francisco
TOKYO, Japan, September 8, 2021 -- SymBio Pharmaceuticals Limited (Headquarters: Tokyo,"SymBio") today announced that a non-clinical study to investigate the anti-tumor efficacy ofbrincidofovir IV (BCV) against brain tumors was initiated at the Brain Tumor Center, Department ofNeurological Surgery, University of California, San Francisco (UCSF).
The principal investigator of this study, Tomoko Ozawa, M.D., Ph.D. (Co-Director, UCSF Brain Tumor
Center Preclinical Therapeutic Testing Core) commented that she is hopeful that the findings from thestudy will lead to new treatments for refractory brain tumors.
Statement from Mr. Fuminori Yoshida, President and Chief Executive Officer of SymBio: “BCV has awide range of antiviral effects against dsDNA viruses and is expected to have antitumor effect. Thisstudy will help to elucidate the effects of BCV on refractory brain tumors and its mechanism of action,and is aimed toward the development of new therapies."
The Company does not expect the information presented herein to have any material impact on its
financial outlook for the fiscal year ending December 2021.

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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 the agreement, Chimerix grants
SymBio exclusive worldwide rights to develop, manufacture, and commercialize BCV in all humanindications, excluding the prevention and treatment of orthopox infections (which includes smallpoxand monkeypox).
About UCSF Brain Tumor Center
It is one of the leading medical institutions in the United States that provides state-of-the-art
molecular tumor profiling, targeted drug treatment, non-drug treatment, and radiotherapy for braintumors. It has over 25 state-of-the-art research and the largest clinical trial program in the country todevelop new therapies for refractory tumors.
https://braintumorcenter.ucsf.edu/why-choose-ucsf-brain-tumor-care
About Chimerix
Chimerix is a development-stage biopharmaceutical company dedicated to accelerating theadvancement of innovative medicines that make a meaningful impact in the lives of patients livingwith cancer and other serious diseases. In June 2021, the U. S. Food and Drug Administration
granted approval of TEMBEXA® for the treatment of smallpox as a medical countermeasure.
Chimerix has two other advanced clinical-stage development programs, ONC201 and dociparstat
sodium (DSTAT). ONC201 is currently in a registrational clinical program for recurrent H3 K27Mmutant glioma and blinded independent central review is expected later in 2021. DSTAT is indevelopment as a potential first-line therapy in acute myeloid leukemia. For further information,please visit the Chimerix website, www.chimerix.com.
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: Menlo Park, California, President: Mr. Fuminori Yoshida).
The Company’s underlying corporate mission is to “deliver hope to patients in need” as it aspires to bea leading global specialty biopharmaceutical company dedicated to addressing underserved medicalneeds.

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