> It does not provide an accurate signal for what the results would be if we gave them to less sick people.

It provides an excellent signal because we want to prove that these drugs are doing something that the standard of care is unable to.

There's this sense that medicine is easy and some evil cabal are limiting health to their cronies. Most medications never get to trial for their intended indications, and most fail trials. There's no reason to believe oncology medications are somehow uniquely unlikely to go through this well-described process of failure.