In a clinical trial, the physician is referred to as the investigator. The study sponsor develops the treatments and choose qualified investigators to work on the clinical trials.
Most clinical trials take place in four steps or phases.
I trials are performed to determine how the drug affects the human body, how much medicine is safe and to determine how the drug should be administered. I trials may involve patients with the disease under study or normal human volunteers. These trials provide information about how well a drug works, and generates more information on the safety and benefit of the drug. A Phase III trial is held to see if the current practice is the best way to treat a patient, or if a new drug treatment or device provides better treatment. Phase III trials compare a new drug, combination of drugs, or procedure with a current standard of treatment.