I agree a company could not take the path I suggested with current thinking as my path is more of finding the maximum tolerance from the top and working backward.

Put it another way: You have a virus that will kill everyone in a short time. You have to test a possible cure on people as you will need the strongest dose possible. How do you go about it with a short time constraint? I would work from both ends. Seems only logical to me.

Now take my scenario of needing to find a max dose NOW to solve a massive plague or risk wiping out the earth via a virus and tone it down just a bit to work against cancer.

I do realize my scenario is just a random thought that has no chance in hell of becoming allowable based on current world thinking.