It's a very understandable mindset and I tend to sympathize with it. On the other hand, fast-tracked does not necessarily mean less safe.
As far as my understanding for clinical trials goes, we can still have the exact same tests with the exact same criteria and quality but still speed up the overall process. Simply by eliminating the default waterfall and accepting higher financial risk. (Also higher medical risk, but only within the trials, not for the end-product).
Usually, one would run the various trials strictly in order:
trial_stage = 0;
while (trial_stage < 4)
execute(trial_stage)
if (evaluate(trial_stage) == success)
trial_stage++
do
Under pressure, we can start the next stage while the previous one is not finished yet. This means higher financial risk, as you are investing already into stage II even if you do not know if stage I will in the end be successful. This also implies higher medical risk for stage II but this risk stays within the trials.