Today's PR means nothing. That's why it's down pre-market. Sapacitabine had people living 3 years out on their pilot. In the Daco-016 trial (Dacogen versus Cytarabine), Cytarabine (the control) exceeded Dacogen at the end of the curve. Any delay could be the control or active arm.
Or is the placebo group doing better than expected? Or have the standards of care improved?
One thing to understand about these studies is that patient treatment doesn't end after they progress. They get the best possible care, including other approved drugs. The application of other treatments after progression may have improved markedly since the study was designed and implemented four or five years ago. That would extend OS in both arms, leading to the delay in unblinding.
Maybe vosaroxin is superior, but that's not a given in this situation.