July 9, 2020
SymBio Pharmaceuticals Limited
Fuminori Yoshida
Representative Director
President and Chief Executive Officer(Securities Code: 4582)

Onconova Therapeutics Announces Publication of Phase 1 Results in Leukemia Research
Exploring Oral Rigosertib in Combination with Azacitidine in Higher-Risk MDSTOKYO, Japan, July 9, 2020 -- SymBio Pharmaceuticals Limited (Headquarters: Tokyo, "SymBio")
today announced that its U.S. licensor for Rigosertib, Onconova Therapeutics, Inc. (Headquarters:Newtown, PA, “Onconova”), announced on July 7, 2020 (EST) that the e-publication of results from aPhase 1 company-sponsored study of oral rigosertib in combination with standard dose azacitidine in
the treatment of patients diagnosed with either higher-risk myelodysplastic syndrome (HR-MDS) oracute myeloid leukemia (AML) in the international hematological malignancy journal Leukemia

Research.
This publication reports the results of an open-label, dose-escalating Phase 1 study with thecombination oral of rigosertib and standard dose azacitidine administered sequentially to patientsdiagnosed with HR-MDS following HMA-failure, or relapsed/refractory AML. The study objectives
were to assess safety and determine the recommended Phase 2 dose (RP2D) for future studies. The
study evaluated three dose cohorts of oral rigosertib with no dose-limiting toxicities reported. In
addition, the oral rigosertib/azacitidine combination demonstrated an overall response rate of 7/9(78%) in patients with HR-MDS and 2/7 (29%) in patients with AML. The Phase 2 part of the study isongoing. Additional details are available on www.clinicaltrials.gov (NCT01926587).
For Onconova's full press release, please visit Onconova's website:
https://investor.onconova.com/press-releases

1About Rigosertib
Rigosertib is a small molecule inhibitor that has a new mechanism of action: it inhibits the activationof RAS as an oncogene-related product, thereby blocking the action of multikinases, including PI3K,and inhibits cellular signaling in cancer cells necessary for their survival and proliferation, thus
killing cancer cells. SymBio obtained the development and commercialization licensing rights for
Rigosertib from Onconova in July, 2011 for Japan and Korea.
About Onconova Therapeutics, Inc.
Onconova Therapeutics, Inc. is a Phase 3-stage biopharmaceutical company focused on discoveringand developing novel drugs to treat cancer, with an initial focus on myelodysplastic syndromes(MDS). Onconova has a pipeline of proprietary targeted agents designed to work against specificcellular pathways that are important in cancer cells. For more information, please visit
https://www.onconova.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., 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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