Feb 19 Onconova Therapeutics Inc said its experimental blood disorder drug did not meet the main goal of a late-stage trial, sending its shares down 45 percent in extended trading.
The company's lead drug, rigosertib, is being studied as a potential treatment for patients with a higher risk of myelodysplastic syndromes who had not responded to prior therapy.
Myelodysplastic syndromes is a group of blood disorders that often precede leukemia.
The company said rigosertib did not increase the overall survival rate in such patients when compared to patients on best supportive care.
Onconova said preliminary safety analysis indicated the drug was generally well tolerated in the trial.
In December last year, the biopharmaceutical company had stopped the development of rigosertib for advanced pancreatic cancer following a review of interim late-stage results.
Since then the company's shares have fallen a little more than 15 percent and closed at $13.86 on Wednesday. The stock was trading at $8.35 in extended trading. (Reporting by Shailesh Kuber; Editing by Don Sebastian and Savio D'Souza)