June 29, 2012
SymBio Pharmaceuticals Limited
Fuminori Yoshida
Representative Director
President and Chief Executive Officer

SYMBIO INITIATES JAPANESE PHASE I TRIAL OF RIGOSERTIB (SYB L-1101)
IN RELAPSED/REFRACTORY MDSTOKYO, Japan, June 29, 2012 -- SymBio Pharmaceuticals Limited (JASDAQ: 4582) announced today that itcommenced enrollment in a Phase I clinical trial using intravenous rigosertib (SyB L-1101) in
relapsed/refractory (r/r) myelodysplastic syndrome (MDS) patients in Japan.
Under the terms of the license agreement concluded with Onconova Therapeutics, Inc. in July, 2011, SymBio
has an exclusive license to develop and commercialize rigosertib in Japan and Korea.
Rigosertib is a patent protected multi-kinase inhibitor with a unique mechanism of action. Patients with MDS
often require frequent blood transfusions due to the development of severe anemia (decrease in number ofred blood cells), with a high rate of progression to acute myelogenous leukemia (AML). There are an
estimated 9,000 MDS patients in Japan alone. Currently there is no approved drug for MDS patients who failfrontline treatment with hypomethylating agents, and there is an urgent need to develop new therapies to treat
r/r and frontline MDS patients.

Onconova is conducting advanced clinical trials with rigosertib in the US and EU for the treatment of MDS andsolid tumors. A pivotal Phase III trial for the treatment of r/r MDS is underway in more than 70 US/EU centers.
The US FDA has granted orphan drug designation for the use of rigosertib in MDS, and has agreed to aSpecial Protocol Assessment (SPA) for the r/r MDS Phase III trial design. Other ongoing advanced trials inlow-risk transfusion dependent MDS (employing oral rigosertib) and in metastatic pancreatic cancer(employing a rationally designed combination therapy incorporating rigosertib) are also underway in the USand India.

[Please read the following for additional 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 Syndromes (MDS)MDS represent a group of diverse myeloid (bone marrow) stem cell disorders with a poor prognosis thatprogressively affect the ability of bone marrow to produce normal red blood cells, white blood cells, andplatelets. Blood stem cells 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 a higher likelihood of developing AML and a poorer prognosis. MDS and AML are blood
disorders widely recognized as being difficult to manage with limited therapeutic options available for patients,
especially those with drug-resistant disease. The risk of MDS increases with age and treatment is moredifficult in elderly populations.

About Rigosertib
Rigosertib (ON 01910.Na) is a small molecule inhibitor of critical pathways important in the growth andsurvival of cancer cells. Extensive Phase I and Phase II studies with rigosertib have been conducted atleading institutions in the US and abroad in more than 500 patients with solid tumors and hematologicalcancers, including MDS and AML. An ongoing multi-site Phase III trial, called ONTIME (ON 01910.Na Trial InMyelodysplastic SyndromE), is being conducted in MDS patients by Onconova under a SPA from the US FDA.
The ONTIME trial is being supported by an award from the Therapeutics Acceleration Program of The
Leukemia & Lymphoma Society® (LLS). The FDA has granted Orphan Drug Designation for the use ofrigosertib in MDS. The clinical program in solid tumors is also advancing, with the Phase II/III combination
ONTRAC trial (ON 01910.Na TRial in Patients with Advanced Pancreatic Cancer). Onconova has also
initiated a Phase II trial, ONTARGET (Oral ON 01910.Na in TrAnsfusion-RequirinG patients with
myElodysplasTic syndrome), studying a transfusion-dependent low-risk MDS patient population with the oral
formulation of rigosertib. A patent for rigosertib has been issued in the US, with corresponding international
patent coverage.
About Onconova Therapeutics®, Inc.
Onconova Therapeutics, based in Newtown, PA and Pennington, NJ, discovers and develops novel small
molecule therapeutics directed at targets involved in signal transduction, cell-cycle, and DNA repair. These
product candidates are proprietary new chemical entities derived from non-ATP competitive chemotypes. In
addition to rigosertib (ON 01910.Na). Onconova is developing two other product candidates in clinical trials:
ON 01210.Na (Ex-RAD®), an injectable and oral radioprotectant, and ON 013105 for refractory lymphomas.
The oncology preclinical pipeline at Onconova includes inhibitors of Plk2, CDK, JAK, and Bcr-Abl pathways
and a novel immunoconjugate platform for arming therapeutic antibodies. For additional information, please
visit Onconova’s homepage at 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 pharmaceutical company in Asia Pacific dedicated to addressing
underserved medical needs in oncology, hematology and autoimmune diseases. The company’s lead drugcandidate, bendamustine hydrochloride, has been successfully developed and launched in Japan forrelapsed/refractory indolent non-Hodgkin’s lymphoma (NHL) and mantle cell lymphoma (MCL). SymBio isalso actively developing bendamustine in frontline indolent NHL and relapsed/refractory multiple myeloma(MM) in Japan. As well as Japan, bendamustine has been launched in Hong Kong, Singapore, Korea andTaiwan. For additional information, please visit our homepage at http://www.symbiopharma.com.