Onconova Reports Novel Dual Targeting of ARK5, CDK4/6 by Pre-Clinical Compound, ON 123300 at AACR

Onconova Therapeutics, Inc.

, a clinical-stage biopharmaceutical company focused on discovering and developing novel products to treat cancer, today announced the presentation of pre-clinical data for its first-in-class dual inhibitor of ARK5 and CDK4/6 at the 2016 AACR Annual Meeting being held April 16-20, 2016 at the Ernest N. Morial Convention Center in New Orleans, LA. The poster presentation by investigators from the Icahn School of Medicine at Mount Sinai and the University of Nebraska Medical Center, compared the activity of ON 123300 to Ibrance® (palbociclib), an FDA approved CDK4/6 inhibitor. The studies revealed that both compounds could inhibit CDK4/6 but only ON 123300 targeted ARK5, a kinase that regulates cancer cell metabolism by increasing glutamine uptake. Using colorectal cancer cells as a model, the researchers demonstrated that ARK5 inhibition by ON 123300 reduced glutamine uptake leading to diminished cellular ATP levels. Most notably, the inhibitory activity of ON 123300 on ARK5 and CDK4/6 resulted in the activation of programmed cell death, while selective CDK4/6 targeting by palbociclib merely resulted in cytostasis. "This pre-clinical poster adds to previous data demonstrating the important differentiating features of ON 123300," said Manoj Maniar, Ph.D., Senior Vice President for Product Development at Onconova. "We believe that the inhibition of ARK5 and induction of apoptosis by ON 123300 represent an improvement over the current generation of CDK4/6 inhibitors." A full copy of the AACR poster titled, "Dual targeting of ARK5 and CDK4 pathways with ON 123300 as a therapeutic strategy," can be accessed by visiting "Posters" in the Investors and Media section of Onconova's website at www.onconova.com.