Onconova Therapeutics, Inc. ( ONTX ) recently provided results on its most advanced candidate, rigosertib, from the phase III study, ONTIME.
Rigosertib failed to meet its primary endpoint of significant improvement in median overall survival compared to best supportive care (BSC) in the ONTIME study. The multi-center, randomized, controlled ONTIME study evaluated patients with higher risk myelodysplastic syndromes (MDS) who had progressed on, failed or relapsed after prior therapy with hypomethylating agents (HMAs).
The median overall survival of 8.2 months for IV rigosertib plus BSC arm was not statistically significant when compared to 5.8 months for placebo.
However, the effects of the treatment were seen in certain subgroups. In a subgroup of patients who had progressed on or failed previous treatment with HMAs, the median overall survival was 8.5 months for IV rigosertib plus BSC arm compared with 4.7 months for placebo.
Further analysis is underway to identify potential survival benefit in other subsets of patients.
Additional details from the ONTIME study will be presented at the annual meeting of the American Society of Clinical Oncology (ASCO).
Onconova is developing rigosertib in partnership with Baxter International Inc. ( BAX ) (commercialization rights in Europe) and SymBio Pharmaceuticals (Japan and Korea). Onconova will commercialize in all other territories.
Rigosertib is also being evaluated in a phase III study for metastatic pancreatic cancer, phase II study for transfusion-dependent lower risk MDS, and a phase II study for head and neck cancers.
Onconova carries a Zacks Rank #3 (Hold). We expect investors to react negatively to this news. The stock is down in pre-market trading.