Clinical Trials

Clinical trials are conducted to evaluate and test new pharmaceuticals before they are approved and brought to market. Clinical trials were traditionally conducted in three phases, with a fourth phase added to monitor post-marketing findings. The trials at each phase have a different purpose and help researchers evaluate the potential treatment in a number of ways to ensure its safety and efficacy.

Phase I trials

Researchers test an experimental drug or treatment in a small group of people for the first time. The researchers evaluate the treatment’s safety, determine a safe dosage range, and identify side effects.

Phase II trials

The experimental drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.

Phase III trials

The experimental study drug or treatment is given to large groups of people. Researchers confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the experimental drug or treatment to be used safely.

Phase IV trials

Post-marketing studies, which are conducted after a treatment is approved for use by the FDA, provide additional information including the treatment or drug’s risks, benefits, and best use.