NEWTOWN, Pa. & PENNINGTON, N.J.--(BUSINESS WIRE)--Onconova Therapeutics, Inc., announced today the advancement of the oral formulation of rigosertib (Estybon®, ON 01910.Na), an anti-cancer agent with demonstrated activity in solid tumors and hematologic malignancies, into a new Phase II study. The intravenous (IV) formulation of rigosertib is currently in a pivotal Phase III trial for refractory myelodysplastic syndromes (MDS) in the U.S. and EU.