Onconova Therapeutics' ($ONTX) shares took a 16% beating Tuesday night after the company's top prospect, rigosertib, failed a Phase III trial in patients with pancreatic cancer.
The company is pulling the plug on its study after learning in an interim analysis that rigosertib paired with gemcitabine was unlikely to move the needle on overall survival compared to the old drug on its own. Onconova has a lot riding on rigosertib, a multikinase inhibitor that targets the mitotic and PI-3 kinase pathways, and the pancreatic failure is a major setback for the Newtown, PA, biotech.
The news sent Onconova's shares into a tailspin after markets closed Tuesday, falling 16% to $13.75.
"We are very disappointed by these results, especially for patients with metastatic pancreatic cancer, given the lack of meaningful treatment options," CEO Ramesh Kumar said in a statement. "We would like to thank the patients and investigators for their participation in this trial."
With a proposed pancreatic cancer indication cast aside, rigosertib's future now rests on a Phase III study in patients with myelodysplastic syndromes and a Phase II trial testing an oral formulation of the drug in MDS patients with less severe symptoms. If all goes well in the Phase III study, Onconova plans to file an NDA for rigosertib in the second half of 2014, the company has said, plans that shouldn't be affected by the drug's failure in pancreatic cancer.
Onconova hauled in $79.6 million in an IPO over the summer, riding high on investor confidence in rigosertib's potential after mid-stage results demonstrated objective responses in 12 MDS patients, with 5 experiencing complete bone marrow responses.
- read the statement