time for a reality check, page-49

The criteria are always strict for PI studies that essentially test for safety. The researchers will be doing a battery of tests to see that it is safe. Using candidates that are not in the best shape, are elderly, overweight, possibly pregnant, or use medications for other conditions muddy the results of these tests and could see the trial halted because they wouldn't know whether the drug is causing them or not.

PIIb will see a relaxation of patient criteria.