Onconova enters agreement with FDA for Estybon Phase 3 trial SPA

Onconova Therapeutics^®, Inc. announced agreement with the U.S. Food and Drug Administration (FDA) regarding a Special Protocol Assessment (SPA) for the design of a pivotal Phase 3 trial for Estybon™ (ON 01910.Na) as monotherapy in patients with myelodysplastic syndromes (MDS), diseases affecting the production of healthy blood cells in the bone marrow. The SPA provides FDA evaluation and acceptance of a clinical trial protocol, including trial size, clinical endpoints and data analysis, and provides further agreement that the Phase 3 study design adequately addresses objectives in support of a regulatory submission.

“The Phase 1 and 2 Estybon™ data which were presented at the Best of ASH session of the 2009 ASH conference, demonstrated promising activity and outcomes for MDS patients treated with Estybon™ and provided heightened awareness of the potential therapeutic role of a Cyclin D targeted therapy for these patients.”

The Estybon™ MDS trial will be conducted by Onconova in the U.S. and Europe and will enroll patients with excess blasts who are resistant or intolerant to or have relapsed after treatment with currently approved treatments. The Onconova trial will compare the efficacy and safety of Estybon™ to Best Supportive Care (BSC). Patient enrollment in the U.S. is expected to begin in 4Q 2010. Ongoing studies of Estybon™ have enrolled a broad range of MDS patients with various cytogenetic markers and classifications. Results from these MDS trials, including survival data will be presented at the annual meeting of the American Society of Hematology (ASH) in December 2010 in Orlando, FL.

James F. Holland, M.D., Distinguished Professor of Neoplastic Diseases at Mount Sinai School of Medicine and Onconova Clinical Advisory Board member, a Lasker award recipient, commented: "More active agents are needed to improve survival for patients with MDS. We are very excited about this Phase 3 trial, which is based on the encouraging Phase 2 data. The activity of ON 01910.Na is remarkable as a single agent and when combined with other chemotherapeutic agents. These promising results could prove beneficial in multiple cancer indications."

"Securing the SPA for Estybon™ in MDS is an important step in the development of this innovative therapy for cancer patients," said Michael Hoffman, Chairman, Board of Directors of Onconova. "We are optimistic that the strikingly positive results from ongoing trials, combined with the anticipated data from this registration trial, will help establish the utility of Estybon™ in this patient population, presently facing limited treatment options. We are also pursuing solid tumor indications for Estybon™ which is broadly active in a variety of tumor types."

Dr. Francois Wilhelm, Chief Medical Officer of Onconova added, "The Phase 1 and 2 Estybon™ data which were presented at the Best of ASH session of the 2009 ASH conference, demonstrated promising activity and outcomes for MDS patients treated with Estybon™ and provided heightened awareness of the potential therapeutic role of a Cyclin D targeted therapy for these patients."

"The Leukemia & Lymphoma Society (LLS) is committed to the rapid advancement of therapies that have strong potential for the treatment of patients with MDS" said Louis J. DeGennaro, LLS Chief Mission Officer. "LLS continues its support for the development of Estybon™ through our collaboration with Onconova announced in June 2010. We see this SPA as a significant step toward making this drug available to patients."