February 26, 2021
SymBio Pharmaceuticals Limited
Fuminori Yoshida
Representative Director
President and Chief Executive Officer(Securities Code: 4582)

Chimerix Announces FDA Extends PDUFA Date of New Drug Applicationfor Brincidofovir as a Medical Countermeasure for Smallpox to July 7, 2021

TOKYO, Japan, February 26, 2021 -- SymBio Pharmaceuticals Limited (Headquarters: Tokyo,"SymBio") today announced that Chimerix Inc. (Headquarters: Durham, NC, "Chimerix") announced
on February 25, 2021 (US EST) that they received notification from the FDA that the Prescription
Drug User Fee Act (PDUFA) goal date for review of brincidofovir (BCV) as a medical countermeasurefor smallpox has been extended three months to July 7, 2021.
SymBio, pursuant to a license agreement with Chimerix entered into on September 30, 2019,obtained the exclusive worldwide rights to develop, manufacture, and commercialize BCV in all
human indications, excluding the prevention and treatment of orthopox infections (which includes
smallpox and monkeypox), and SymBio is preparing to initiate a global study of BCV targeting
adenovirus (AdV) infections occurring after hematopoietic stem cell transplantation.
Chimerix is developing BCV as a potential medical countermeasure for smallpox under an ongoingcollaboration and funding provided by the Biomedical Advanced Research and Development
Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response
within the U.S. Department of Health and Human Services. Chimerix does not expect a later FDA
action date will impact the timing of the BARDA request for proposal, which is expected this quarter,
nor the potential timing of first shipments of BCV to the strategic national stockpile, expected in thesecond half of this year, according to “Chimerix Reports Fourth Quarter and Year End 2020 Financial
Results and Provides Operational Update” published on February 25, 2021 (US EST).
For more information, please see Chimerix’s website:
https://ir.chimerix.com/press-releases

1[Contact]
Investor Relations
Tel: +81 (0)3 5472 1125
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. Its three most advanced clinical-stage development programs
are BCV, ONC201 and DSTAT. BCV is an antiviral drug candidate developed as a potential medical
countermeasure for smallpox and is currently under review for regulatory approval in the UnitedStates. ONC201 is currently in a registrational clinical program for recurrent H3 K27M-mutant
glioma and a confirmatory response rate assessment is expected later this year. DSTAT is indevelopment as a potential first-line therapy in acute myeloid leukemia and as a potential treatment
for acute lung injury in hospitalized COVID-19 patients. For further information, please visit theChimerix website, www.chimerix.com.
About the Global License Agreement for Brincidofovir
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). For further information, please see theSymBio’s press release dated October 1, 2019, https://www.symbiopharma.com/news/20191001.pdf
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.

2