phase IV trial
(fayze for tryle)
After a treatment has been approved and is being marketed, it is studied in a phase IV trial to evaluate side effects that were not apparent in the phase III trial. Thousands of people are involved in a phase IV trial.
For more information, see Breastcancer.org's Clinical Trials section or read about studies in Research News.
Audio contributed by: Marisa Weiss, M.D.