Onconova Therapeutics, Inc. to Present New Data on Rigosertib and Earlier-Stage Programs at the 2015 American Association of Cancer Research (AACR) Annual Meeting

NEWTOWN, Pa., April 7, 2015 (GLOBE NEWSWIRE) -- Onconova Therapeutics, Inc. (Nasdaq:ONTX) a clinical-stage biopharmaceutical company focused on discovering and developing novel products to treat cancer, today announced the presentation of pre-clinical data of its leading proprietary compounds at the 2015 AACR Annual Meeting being held April 18-22, 2015 at the Pennsylvania Convention Center in Philadelphia, PA.

Three abstracts relating to clinical-stage compounds rigosertib and briciclib, and three abstracts relating to pre-clinical-stage compounds, are scheduled to be presented. The presentations are listed below.

"Our presence at AACR will showcase the innovative advances in cancer treatment being pioneered by Onconova and our collaborators," said Ramesh Kumar, Ph.D., President and CEO of Onconova. "The AACR presentations will highlight the depth of our clinical and pre-clinical pipeline, including rigosertib for the treatment of myelodysplastic syndromes, briciclib for the treatment of advanced solid tumors refractory to current therapies, as well as multiple pre-clinical oncology programs. We are excited to detail some of our most recent scientific advances at the prestigious AACR conference."      

Bone marrow culture system for testing rigosertib activity in lower-risk myelodysplastic syndromes (LR-MDS) patients

• "An in vitro platform to dissect drug responsiveness in refractory anemia with ringed sideroblasts (RARS)." Abstract number: 2425, 4/20/2015, 1:00 PM - 5:00 PM ET

Mechanism of action studies for rigosertib

• "Structure-function analysis of RPL18A, a putative binding target of rigosertib." Abstract number: 694, 4/19/2015, 1:00 PM - 5:00 PM ET

Development of orally bioavailable analog of briciclib

• "Potent anticancer activity of an orally bioavailable small molecule, ON 013100, and its water soluble derivative, briciclib, a clinical-stage IF4E-targeted agent." Abstract number: 1649, 4/20/2015, 8:00 AM - 12:00 PM ET 

Activity of pre-clinical CK2 inhibitor, ON 108600, against cancer stem cells and paclitaxel resistant triple-negative breast cancer (TNBC)

• "The dual CK2/TNIK inhibitor, ON108600 targets cancer stem cells and induces apoptosis of paclitaxel resistant triple-negative breast cancer cells." Abstract number: 4453, 4/21/2015, 1:00 PM - 5:00 PM ET

Development of nanosuspension formulation of pre-clinical PLK2 inhibitor, ON 1231320 (GBO-006), for testing in TNBC models

• "Development of lipid-based nanosuspension formulation of first-in-class PLK2 inhibitor GBO-006 to treat triple-negative breast cancer." Abstract number: 1661, 4/20/2015, 8:00 AM - 12:00 PM ET

Identification of novel PLK2 substrates using PLK2 inhibitor, ON 1231320 (GBO-006)

• "Identifying novel substrates of PLK2 using a chemical genetics approach." Abstract number: 2450, 4/20/2015, 1:00 PM - 5:00 PM ET

About Onconova Therapeutics, Inc.

Onconova Therapeutics is a clinical-stage biopharmaceutical company focused on discovering and 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, the Company's most advanced product candidate, two other candidates are clinical stage, and several candidates are in pre-clinical stages.  For more information, please visit http://www.onconova.com.

About Rigosertib

Rigosertib is a small molecule that inhibits cellular signaling by acting as a Ras mimetic. This is believed to be mediated by direct binding of rigosertib to the Ras-binding domain (RBD) found in many Ras effector proteins, including the Raf kinases and PI3K. The initial therapeutic focus for rigosertib is myelodysplastic syndromes (MDS), a group of bone marrow disorders characterized by ineffective formation of blood cells that often converts into acute myeloid leukemia (AML). Clinical trials with intravenous (IV) and oral formulations of rigosertib are being conducted at leading institutions in the U.S. and Europe.

Forward Looking Statements

Some of the statements in this release are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties. These statements relate to future events or Onconova Therapeutics, Inc.'s future operations, clinical development of Onconova's product candidates and presentation of data with respect thereto, regulatory approvals, expectations regarding the sufficiency of Onconova's cash and other resources to fund operating expenses and capital expenditures, Onconova's anticipated milestones and future expectations and plans and prospects. Although Onconova believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements. Onconova has attempted to identify forward-looking statements by terminology including "believes," "estimates," "anticipates," "expects," "plans," "intends," "may," "could," "might," "will," "should," "approximately" or other words that convey uncertainty of future events or outcomes. These statements are only predictions and involve known and unknown risks, uncertainties, and other factors, including those discussed under the heading "Risk Factors" in our most recent Annual Report on Form 10-K and quarterly reports on Form 10-Q.

Any forward-looking statements contained in this release speak only as of its date. We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events.

CONTACT: Onconova Therapeutics

         Benjamin Hoffman, 267-759-3036

         bhoffman@onconova.us