December 27, 2012
SymBio Pharmaceuticals LimitedFuminori Yoshida
Representative Director
President and Chief Executive Officer

Clinical Trial Notification Accepted by Japanese Regulatory Agency for SymBio’s
Phase I Oral Rigosertib (SyB C-1101) Trial in Frontline MDSTOKYO, Japan, December 27, 2012 – SymBio Pharmaceuticals Limited (JASDAQ: 4582) announced
that clinical trial notification (CTN) has been accepted by the Japanese Pharmaceuticals and Medical
Devices Agency (PMDA) for its Phase I oral rigosertib (SyB C-1101) clinical trial in frontline
myelodysplastic syndrome (MDS) patients. This CTN enables SymBio to proceed with clinical trials andis comparable to an Investigational New Drug (IND) application in the U.S.
Under the terms of a license agreement with Onconova Therapeutics, Inc. signed July, 2011, SymBio
has an exclusive license to develop and commercialize rigosertib in Japan and Korea. Rigosertib is anovel, patent protected inhibitor of PI3-Kinase and PLK pathways in cancer cells.
Patients with MDS often have severe anemia (decrease in number of red blood cells) or low platelet
counts, and have a high rate of progression to acute myelogenous leukemia (AML). The prevalence ofMDS is estimated to be 11,000 patients in Japan alone. Currently, there is no approved therapy for MDS
patients after they fail frontline therapy with hypomethylating agents. As such, there is an urgent need todevelop therapies to treat refractory/relapsed and frontline MDS.
Onconova Therapeutics Inc. is currently conducting late-stage clinical trials with rigosertib(ON 01910.Na) in the U.S., Europe and India for the treatment of hematologic malignancies and solidtumors. A pivotal trial in refractory/relapsed MDS is underway using the intravenous (IV) formulation ofrigosertib. The U.S. FDA has granted orphan drug designation for rigosertib in MDS and has agreed to aSpecial Protocol Assessment (SPA) for this Phase III trial. Onconova is also developing an oral
formulation of rigosertib as a frontline treatment for MDS.
In addition to the Phase I trial with oral rigosertib (SyB C-1101) in frontline MDS, a Phase I trial inrefractory/relapsed MDS patients using the IV formulation of the drug is underway in Japan. SymBio isdeveloping rigosertib expeditiously in order to make this innovative drug available to patients in need.
[Please see the following for further information on MDS, Rigosertib, and Onconova ][Contact]
Hiroki Maekawa
Board Director, Corporate Officer, Chief Financial Officer
Tel: +081(0)3 5472 1125

Note to Editors

About Myelodysplastic Syndrome (MDS)MDS represents a group of diverse myeloid (bone marrow) stem cell disorders that gradually affect theability of bone marrow to produce normal red blood cells, white blood cells, and platelets. Blood stemcells fail to mature into healthy blood cells; and the immature blood cells, called blasts, do not function
normally and either die in the bone marrow or enter the blood. A higher percent of blasts is linked to ahigher likelihood of developing leukemia and poorer overall prognosis. The risk of MDS increases withage and the disease commonly affects the elderly.
About Rigosertib
Rigosertib (ON 01910.Na) is a small molecule inhibitor that targets the PI3- kinases and the PLK mitotic
pathways, critical pathways to the growth and survival of cancer cells. Phase I-III studies with rigosertib
have been conducted at leading institutions in more than 800 patients with solid tumors andhematological cancers, including myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). A
multi-site Phase III trial (ONTIME) in MDS patients is being conducted under a Special ProtocolAssessment (SPA) from the U.S. Food and Drug Administration (FDA) and is being supported by anaward from the Therapeutics Acceleration Program of The Leukemia and Lymphoma Society. Both theFDA and European Medicines Agency have granted Orphan Drug Designation for the use of rigosertib inMDS. The rigosertib clinical program in solid tumors is also advancing in a Phase III adaptive design trial(ONTRAC) for pancreatic cancer. ONTRAC is a Phase III, multicenter, randomized, controlled study (withan interim analysis for futility) that compares the efficacy and safety of gemcitabine alone vs. rigosertib
combined with gemcitabine in patients with previously untreated metastatic pancreatic cancer.
About Onconova Therapeutics, Inc.
Onconova Therapeutics, based in Newtown, PA and Pennington, NJ, discovers and develops novel small
molecule therapeutics directed against targets involved in signal transduction, cell-cycle, and DNA repair.
The most advanced product, rigosertib (ON 01910.Na), is now in a pivotal trial being conducted under aSpecial Protocol Assessment (SPA) from the U.S. Food and Drug Administration (FDA) for
myelodysplastic syndrome (MDS), as well as in a Phase III trial for pancreatic cancer. In addition torigosertib, Onconova is developing two other clinical stage products: Ex-RAD® (a radioprotectant) andON 013105 (a novel anti-cancer agent initially directed toward refractory lymphoma, including mantle celllymphoma). For additional information, please visit http://www.onconova.com.
About SymBio Pharmaceuticals Limited
SymBio Pharmaceuticals Limited, based in Tokyo, Japan, was established in March, 2005, by Fuminori
Yoshida, who previously served concurrently as Corporate VP of Amgen Inc. and founding President ofAmgen Japan. The company’s underlying corporate mission is to “deliver hope to patients in need” as itaspires to be a leading specialty pharma in Asia Pacific dedicated to addressing underserved medicalneeds with focus in the areas of oncology, hematology and autoimmune. The company’s lead drugcandidate, bendamustine hydrochloride, has been successfully developed and launched in Japan forrefractory/relapsed indolent non-Hodgkin’s lymphoma (NHL) and mantle cell lymphoma. SymBio is also
actively developing bendamustine in frontline indolent NHL, refractory/relapsed aggressive NHL andmultiple myeloma in Japan. The product has been launched in Hong Kong, Singapore, Korea andTaiwan. For additional information, please visit our homepage at http://www.symbiopharma.com.