Phases, Benefits and Risks of Clinical Trials

Phases of Clinical Trials

Clinical trials are done in phases. Each phase of the clinical trial has a different purpose.

• PHASE 1 – Experimental treatment is given to a small group (20 to 80 people) for the first time to evaluate its safety, dosage range and side effects.
• PHASE 2 – Experimental treatment is given to a larger group (100 to 300 people) to evaluate its safety and effectiveness.
• PHASE 3 – Experimental treatment is given to large groups (1,000 to 3,000 people) to confirm its effectiveness, monitor side effects and compare to current standard of care treatments or placebo.

If the experimental treatment works well in a Phase 3 trial, researchers can apply to the U.S. Food and Drug Administration (FDA) to ask for permission to make the treatment available to the public. The FDA approval process takes about a year. The FDA’s review process is carried out in different stages to review the clinical trial’s research and data and to decide if it can be a helpful treatment.

In some cases, research continues even after the FDA has approved a treatment. The FDA can ask researchers to conduct a Phase 4 trial in which researchers collect all the information they have on the experimental treatment’s long-term safety and effectiveness after the drug is approved.

Benefits and Risks of Clinical Trials

Potential benefits of clinical trials include:

• Access to new research treatments
• Access to specialists and/or expert care
• Contributing to medical research that can help other people

Potential risks associated with clinical trials include:

• Serious side effects
• Unsuccessful treatment outcome
• Inability to participate in other trials