What is a clinical trial and why are they important?

“Clinical research” refers to studies, or trials, that are done with people as participants in these studies or trials. There are four main phases of these studies that take place before a new drug/therapy/intervention can be approved by the FDA for general use.

Phase I

Study Participants: This phase involves 20 to 100 healthy volunteers or people with the disease/condition.

Length of Study: Several months.

Purpose: To determine the safety and the correct dosage.

Approximately 70% of drugs move to the next phase.

Phase II

Study Participants: This phase involves up to several hundred people with the disease/condition.

Length of Study: Several months to 2 years.

Purpose: To determine efficacy and side effects.

Approximately 33% of drugs move to the next phase.

Phase III

Study Participants: This phase involves 300 to 3,000 people with the disease/condition.

Length of Study: 1 to 4 years.

Purpose: To determine efficacy and monitoring of adverse reactions.

Approximately 25-30% of drugs move to the next phase.

Phase IV

Study Participants: This phase involves several thousand people who have the disease/condition.

Length of Study: Safety and efficacy.

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U.S. Food & Drug Administration, the Drug Development Process, retrieved from: https://www.fda.gov/patients/drug-development-process/step-3-clinical-research

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