Understanding Investigational Drugs

Not all patients respond to approved drugs, for a variety of reasons. For serious and life-threatening illnesses, some patients may want to talk to their Healthcare Provider about trying an investigational drug.

Investigational drugs, sometimes referred to as experimental drugs, are still being studied to determine if they are safe and effective, and how best to use them for their intended purpose. They are different from approved drugs, which began as investigational drugs and have undergone the extensive testing in animals and humans to show that they are safe and effective for treating that illness.

Read more here:
http://www.fda.gov/ForPatients/Other/OffLabel/ucm20041767.htm