What is a Clinical Trial?
A Phase 1 trial evaluates the safety of
a test drug or other rehabilitation therapy
in a small population. Goals included testing the mechanism of action, identifying
potential toxicity and side effects, and establishing dosage range for future
trials. In a Phase II trial, safety is still the most important
issue, but efficacy becomes the more central criterion and the size of the
test group increases. Phase III marks the final pre-marketing
step; if testing in a large group of patients (300-3000) finds that a product
or rehabilitation therapy managed to prove the desired
medical or scientific endpoint(s), and was safe to use, the results will be
submitted to the FDA for approval of the drug's use in the general population.
Side effects are monitored and the benefits of use are compared to other treatments.
It is important to realize that this stepwise process through gradually larger
and more complex protocols protects the patients, improves the understanding
of the medicine being tested, and allows the sponsor to value it.
After a drug is approved by the FDA, it can be marketed.
Postmarketing safety surveillane falls into Phase IV category.
These sorts of trials continue the evaluation of risks and benefits associated
with the therapy after it has been made widely available. For the interested,
an excellent review of this material is available on the web at www.clinicaltrials.gov.