Onconova Therapeutics Inc. reported positive results from its phase 2 study of treating patients suffering from bone marrow disorders with rigosertib.
Rigosertib is a novel small molecule drug candidate meant to treat cancer, with a primary focus on bone marrow disorders.
A total of 64 patients, who had failed the standard of care treatment using hypomethylating agents, took part in the trial.
The study sought to evaluate the response of bone marrow blast cells to rigosertib as a surrogate for overall survival. The results showed treatment with rigosertib lowered bone marrow blast cell count, with 22% of patients achieving marrow complete response and 47% achieving disease stabilization.
In landmark analysis, bone marrow response correlated with overall survival with median overall survival at 3.3 months for progressors, 6.3 months for those achieving disease stabilization and was not reached for patients achieving marrow complete response.
Onconova said the results confirmed findings from earlier studies, thus supporting blast cell response as a potential surrogate marker for improved overall survival in patients who had failed treatment with hypomethylating agents.
The biopharmaceutical company is also testing rigosertib in a multicenter phase 3 INSPIRE trial with overall survival as the primary endpoint.