Hi Pete! Traditionally, cancer trials have not bee

Hi Pete! Traditionally, cancer trials have not been placebo trials. Placebo trials in cancer would historically have been quick death sentence. They haven't been done - but needs are changing with new molecular agents coming forward and trial construction is challenging researchers. Now we're in the time of novel cancer agents. They slow or stop tumor growth, but don't shrink tumors (yet). Their side effects often look like cancer - fatigue, headache, etc. So now researchers feel like they do need placebo trials for cancer research and are working hard on the ethical parameters of doing this.

One model that I like is that one arm of patients receives current standard of care treatment and the investigational drug while the other arm receive current standard treatment only. When those on standard of care only have disease progression - they are allowed to cross over to active treatment group. So the control arm then ends up having a delayed entrance into treatment with new molecule.

Another approach recently used is inclusion of all patients into treatment with investigational drug - then removal of the patients who couldn't tolerate it or whose tumors grew.  The remaining patients become your investigational group. Those who achieve stable tumor or reduction are split into 2 groups. One continues with treatment with novel agent, the other receives placebo. If patient in placebo group shows tumor growth - they are then moved back into treatment group.

So - they're working it out. New rules with this new generation of novel agents.