Here is a helpful link from the American Cancer Society that explains the differences between Phase I, II, III and IV trials.
While the party line is that Phase I trials are only about dose and safety, don’t believe for a second that the researchers and the patients in the trials are not hoping for a strong signal that they have an active drug in the clinic.
Phase III trials are usually where there are at least two different randomized arms to compare the value of the novel therapy against the usual standard of care, and ultimately get FDA approval.
