July 26, 2017
SymBio Pharmaceuticals Limited
Fuminori Yoshida
Representative Director
President and Chief Executive Officer(Securities Code: 4582)

Onconova Announces Establishment of Collaborative
Research and Clinical Program
Evaluating Rigosertib in Pediatric “RASopathies”
TOKYO, Japan, July 26, 2017 -- SymBio Pharmaceuticals Limited (Headquarters: Tokyo, "SymBio,")announced today that its U.S. partner, Onconova Therapeutics, Inc. (Headquarters: Newtown, PA,“Onconova”) announced on July 25, 2017 (EDT) the establishment of a collaborative,
multi-institutional research and clinical program to evaluate rigosertib in pediatric RASopathies.
Onconova will initially prioritize Juvenile Myelomonocytic Leukemia (JMML) that sharescharacteristics of adult MDS. In addition, Onconova will collaborate with the National Cancer
Institute on a broad clinical trial for pediatric patients with RASopathies. For more details in
Onconova’s press release, please visit Onconova’s website at http://investor.onconova.com/releases.cfm
In collaboration with Onconova, SymBio continues to be engaged in a global randomized Phase 3
INSPIRE trial for IV rigosertib and a Japanese Phase 1 trial for oral rigosertib in MDS patients.
SymBio obtained the licensing rights for rigosertib from Onconova in July, 2011 and retains thedevelopment rights for Japan and Korea.

1About RASopathies
RASopathies are developmental syndromes usually caused by germline mutations in genes that alter
the RAS subfamily and mitogen-activated protein kinases that control signal transduction.
About Myelodysplastic Syndromes (MDS)MDS patients often require frequent blood transfusions due to the development of severe anemia(decrease in the number of red blood cells), with a high rate of progression to acute myelogenous
leukemia (AML). The number of MDS cases are expected to increase as the population ages. MDS andAML are widely recognized as two blood disorders that are difficult to manage given the limited
therapeutic options available for patients, particularly for patients who have a drug-resistant form ofthe disease. A high unmet medical need clearly exists for the establishment of new effective therapies
to treat both lower-risk MDS and higher-risk MDS.
About Juvenile Myelomonocytic Leukemia (JMML)
Grouped under MDS and myeloproliferative neoplasms (MPNs), JMML is a type of pediatric cancer ofthe blood that mostly affects infancy/early childhood. The incidence rate of JMML is one to two per one
million and the new incidence is estimated at about 20 cases a year in Japan.
About Onconova Therapeutics, Inc.
Onconova Therapeutics, Inc. is a Phase 3-stage biopharmaceutical company focused on discoveringand developing novel products to treat cancer. Onconova's clinical and pre-clinical stage drug
development candidates are derived from its extensive chemical library and are designed to work
against specific cellular pathways that are important in cancer cells, while causing minimal damage tonormal cells. In addition to rigosertib, Onconova's most advanced drug candidate under development,
two other drug candidates are in clinical trials and several other compounds in the pre-clinical stage ofdevelopment. For more information, please visit http://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., 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 with main therapeutic focus in oncology, hematology and pain management.

2