On September 26, 2016 Onconova Therapeutics, Inc. (NASDAQ:ONTX), a Phase 3 clinical-stage biopharmaceutical company focused on discovering and developing novel products to treat cancer, reported receipt of the End-of-Phase 2 meeting minutes from the U.S. Food and Drug Administration (FDA) for the combination of oral rigosertib with azacitidine for the treatment of patients with higher-risk myelodysplastic syndromes (HR-MDS) (Press release, Onconova, SEP 26, 2016, View Source [SID:SID1234515367]).

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

Based on these discussions, Onconova will design a randomized, controlled Phase 3 clinical trial comparing the combination of oral rigosertib plus azacitidine to azacitidine plus placebo in 1st-line HR-MDS patients. The primary endpoint of this pivotal trial will be overall response rate (ORR); ORR will be a composite of complete remission (CR) and partial remission (PR). Onconova could potentially pursue additional available paths from FDA for accelerated or enhanced review and further input on the development of a final trial protocol. Full details of the protocol will be available following completion of all regulatory discussions.

As part of the End-of-Phase 2 meeting with FDA, Onconova presented updated results from its Phase 2 trial of oral rigosertib and azacitidine. These results are expected to be presented by study investigators at a scientific conference later this year.

"We are encouraged that our interactions with FDA resulted in agreement on the patient population to be evaluated and the selection of overall response as the primary endpoint in this pivotal trial," stated Steven Fruchtman, M.D., Chief Medical Officer of Onconova. "We will provide additional details on the design of this trial and the full Phase 2 data set supporting our pivotal study plans at upcoming meetings and scientific conferences later in 2016."

Onconova is developing rigosertib for patients with MDS where there is a paucity of therapeutic options. Two hypomethylating agents (HMAs), azacitidine and decitabine, the mainstays for eligible 1st-line patients, were approved by the FDA more than a decade ago. In addition to the oral rigosertib and azacitidine combination program, Onconova is currently enrolling patients in the global, pivotal Phase 3 INSPIRE trial of IV rigosertib for 2nd-line MDS patients, who have failed HMA therapy. This trial of 225 patients is now enrolling in the U.S., Europe, Japan and Australia.

About Oral Rigosertib

The oral form of rigosertib provides a more convenient dosing for use where the duration of treatment may extend to multiple years. To date, more than 350 patients have been treated with the oral formulation of rigosertib, either as a single agent or in combination with other drugs. Phase 1 studies with oral rigosertib were conducted in hematological malignancies, lower-risk MDS and solid tumors. Combination therapy of oral rigosertib with azacitidine and chemoradiotherapy has also been explored.

About Trial 09-08 (NCT01926587): Combination therapy with oral rigosertib and azacitidine

The current standard of care for higher-risk MDS patients is one of two approved hypomethylating agents (Azacitidine and Decitabine, approved by the FDA in 2004 and 2006). Although these drugs are currently the mainstays in HR-MDS therapy, their overall response rate and duration of benefit is limited to a subset of eligible patients and all responding patients ultimately progress. Therefore, there is an urgent need for developing therapeutic options for newly diagnosed MDS patients. The 09-08 Phase 1/2 trial tested oral rigosertib in combination with injectable azacitidine in a dose ranging study (Phase 1), followed by an expansion cohort (Phase 2) to evaluate the efficacy and safety of the combination. Interim results from this trial were presented at the 2015 ASH (Free ASH Whitepaper) conference indicating that the combination was generally well tolerated and that clinical responses were observed in 23 of 30 MDS patients evaluable for efficacy assessment.1 Both 1st-line and 2nd-line patients were included in this study.