Onconova and SymBio Complete License Agreement for Rigosertib, a Phase III Stage
Multi-Kinase Inhibitor for Cancer
NEWTOWN, Pa. and TOKYO, Japan, July 8, 2011
Onconova Therapeutics, Inc., and SymBio Pharmaceuticals Limited announced today that they will
collaborate to develop and commercialize rigosertib in Japan and Korea. Onconova is conducting
late-stage clinical trials with rigosertib (ON 01910.Na) in the U.S., Europe and India for the treatment of
Myelodysplastic Syndromes (MDS) and solid tumors. A pivotal trial in the refractory/relapsed MDS
clinical program is underway in the U.S. and Europe. The U.S. FDA has granted orphan drug
designation for the use of rigosertib in MDS, and has agreed to a Special Protocol Assessment (SPA) forthe phase III trial design.
In addition to the intravenous product in advanced-stage development, an oral formulation of rigosertib isbeing developed for frontline MDS and other indications. The clinical program in solid tumors is also
advancing with the initiation of a Phase II/III combination trial in pancreatic cancer and Phase II single
agent trial in ovarian cancer.
Under the terms of the agreement, SymBio has an exclusive license for Japan and Korea and willdevelop and commercialize rigosertib in these countries. Onconova will receive an upfront payment anddevelopment milestones tied to the progress of rigosertib, as well as sales milestone payments plus
royalties on net sales. The two companies will enter into an agreement for the supply of development
stage and commercial product.
Rigosertib, a novel styryl benzyl sulfone, is a patent protected multi-kinase inhibitor with a unique modeof action. Currently there is no approved therapy for MDS patients who fail frontline treatment withhypomethylating agents, and there is an urgent need to develop a new class of drugs to treat
refractory/relapsed and frontline MDS patients.
“This is the first commercial transaction for our lead product rigosertib, and we are delighted that
SymBio is our partner in Japan and Korea,” said Dr. Ramesh Kumar, President and CEO ofOnconova. “The broad reach of rigosertib across blood cancers as well as solid tumors, and theability to address previously intractable indications with single agent and combination therapies,
will provide multiple opportunities to serve the unmet medical needs of patients worldwide.”“Following our development agreement for MDS with the Leukemia and Lymphoma Society
announced last year, the SymBio collaboration provides additional validation for the commercial
potential of our lead product.” Mr. Michael Hoffman, Chairman of the Board of Directors ofOnconova added, “We are looking forward to working with SymBio and other partners to bringrigosertib to market expeditiously.”“We are very excited about collaborating with Onconova to develop this new class of agent for MDS, ahard-to-treat cancer,” said Mr. Fuminori Yoshida, President and CEO of SymBio. “Due to the paucity ofeffective therapies to treat MDS patients, especially those who are refractory or have relapsed, we are
fully committed to bringing this much-needed cancer drug to market as nimbly as possible in order toimprove the lives of patients in Japan and Korea. Rigosertib is an excellent strategic fit for SymBio, andthe addition of rigosertib to our pipeline will further strengthen SymBio’s presence in the oncology space
as we capitalize on the synergy between bendamustine and rigosertib.”
About Myelodysplastic Syndromes (MDS)MDS represent a group of diverse myeloid (bone marrow) stem cell disorders with a poor prognosis that
gradually 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 ofblasts is linked to a higher likelihood of developing leukemia and a poorer prognosis. The risk of MDS
increases with age and the disease commonly affects the elderly.
About Rigosertib

Rigosertib (ON 01910.Na) is a small molecule inhibitor of critical pathways important in the growth andproliferation of cancer cells. Extensive Phase I and Phase II studies with rigosertib have been conductedin patients with solid tumors and hematological cancers, including MDS, pancreatic and ovarian cancers.
Based on data from clinical studies that explored various dose regimens of rigosertib, administeredalone or in combination with other chemotherapeutic agents in patients with myelodysplastic syndromes(MDS) or with advanced solid tumors, rigosertib is overall well tolerated. In phase I and II clinical trials inpatients who have a limited number of approved treatments for their diseases, rigosertib has
demonstrated significant bone marrow blast count improvement (at least 50% blast reduction) in 53% of
MDS patients and greater than 50% reduction in CA 19-9 marker in about 36% of patients withpancreatic cancer. The most frequent drug-related adverse events (in at least 10% of patients) in theMDS population were fatigue, dysuria, abdominal pain, nausea and diarrhea. In patients with advanced
solid tumors, the most frequent drug related adverse events (in greater than 10% of patients) wereanorexia, diarrhea, vomiting, nausea, and fatigue. The majority of these drug-related adverse eventswere Grade 1 or 2 in severity (NCI CTCAE). The Phase III ONTIME and Phase II/III ONTRAC studies ofrigosertib are designed to further investigate these results and address the unmet medical needs forMDS and pancreatic cancer patients. A U.S. Patent covering rigosertib has been issued and European
and other international patents are expected to issue shortly.

About Onconova Therapeutics, Inc.

Onconova, based in Newtown, PA and Pennington, NJ, and founded in 1998, discovers and develops
novel small molecule therapeutics targeting signal transduction, cell-cycle, and DNA repair pathways.
Onconova has a novel discovery platform focusing on non-ATP competitive kinase inhibitors, and thecompany is also exploring a new immunoconjugate technology (comprising potent active compounds
and proprietary linkers) for arming monoclonal antibodies for cancer therapy. These products,technologies, and candidates are derived internally from a proprietary library of new chemical entities.
In addition to rigosertib, Onconova is also developing Ex-RAD® (ON 01210.Na) as a novel radiation
protection drug (oral and injection) in collaboration with the U.S. Department of Defense to protect
against radiation injury of tissue and whole body. For additional information, please visit
http://www.onconova.com.

JSB Partners and Dechert, LLP, advised Onconova for this transaction.
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 “delivering 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 the areas of oncology, hematology and autoimmune disease. The first
drug candidate SymBio in-licensed, bendamustine, has been developed for refractory/relapsed indolentnon-Hodgkin’s lymphoma (NHL) and mantle cell lymphoma, and successfully launched in Japan.
SymBio is actively developing bendamustine in frontline indolent NHL, aggressive NHL and multiple
myeloma in Japan. The product has also been launched in Hong Kong and Singapore, with Korea andTaiwan to follow by year end. For additional information, please visit http://www.symbiopharma.com.
Latham & Watkins LLP, advised SymBio for this transaction.
Contact
Onconova Therapeutics, Inc.

SymBio Pharmaceuticals Limited

Kathryn MorrisMr. Hiroki Maekawa, Chief Financial OfficerKathryn@proncall.com

hmaekawa.0701@symbiopharma.com

Tel: 845-635-9828

Tel: +81(0)3 5472 1125

URL: http://www.onconova.com

URL: http://www.symbiopharma.com