March 25, 2020
SymBio Pharmaceuticals Limited
Fuminori Yoshida
Representative Director
President and Chief Executive Officer(Securities Code: 4582)

Onconova Announces Completion of Enrollmentof Phase 3 INSPIRE Trial for IV Rigosertib
TOKYO, Japan, March 25, 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 March 24, 2020 (EST) that it hascompleted the planned enrollment of 360 patients in the INSPIRE trial, Onconova’s Phase 3 study ofIV rigosertib for the treatment of higher risk (HR) Myelodysplastic Syndromes (MDS).
Patients with HR MDS, following progression or failure of patients to respond to previous treatment
with a hypomethylating agent (HMA), have limited treatment options and there is a tremendous
unmet medical need. In collaboration with Onconova, SymBio has participated in the international
study and conducted the clinical trial in Japan. 48 of the 360 patients were enrolled in Japan.
Onconova anticipates reporting topline survival data in the second half of 2020 and presenting theresults at a medical meeting later this year.
For Onconova's full press release, please visit Onconova's website:
https://investor.onconova.com/press-releases
Fuminori Yoshida, President and Chief Executive Officer of SymBio, stated: “Completion of theplanned enrollment in the clinical trial in second line HR MDS is an important milestone. We lookforward to the topline data in which the experimental agent rigosertib can prolong the survival of thepatients.”
In addition to the development of IV rigosertib, SymBio plans to participate in the international studyof oral rigosertib plus azacitidine in first-line and refractory HR MDS patients, for which Onconova iscurrently designing the protocol.

1About myelodysplastic syndromes (MDS)MDS are conditions that can occur the blood-forming cells in the bone marrow become dysfunctional
and thus produce an inadequate number of circulating blood cells. 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 ofMDS cases are expected to increase as the population ages. MDS and AML are widely recognized as
two blood disorders that are difficult to manage given the limited therapeutic options available forpatients, particularly for patients who have a drug-resistant form of the disease. A high unmet
medical need clearly exists for the establishment of new effective therapies to treat both lower-riskand higher-risk MDS. The number of drug-treated MDS patients is estimated to be about 11,000 in
Japan at male-female ratio of 2:1 and majority of the patients are elderly.
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 clinical-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
to normal cells. In addition to Rigosertib, Onconova's most advanced drug candidate underdevelopment, two other drug candidates are in clinical trials and several other compounds are in the
pre-clinical stage of development. 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., 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 medical
needs.

2