Before a medicine is approved to treat patients, it needs to be tested. The goal of clinical trials is to determine if a new test or treatment works and is safe. Clinical trials offer an opportunity to help researchers find better treatments in the future.

Preclinical Studies

Preclinical studies involve research in the laboratory to find out if a drug, procedure, or treatment is likely to be useful. Usually, preclinical studies are not very large. However, these studies must provide detailed information on dosing and toxicity levels.

About Clinical Trials

A clinical study involves research using human volunteers (also called participants) that is intended to add to medical knowledge. There are two main types of clinical studies: clinical trials (also called interventional studies) and observational studies.

Clinical trials are used to determine whether new drugs, diagnostics or treatments are both safe and effective. Carefully conducted clinical trials are the fastest and safest way to find treatments that help people.

Clinical Trial Phases

Clinical trials are broken down into different phases. During a trial, more and more information is gained about the potential treatment, its risks and how well it may or may not work, along with aspects related to quality of life. Clinical trials are categorized as Phase I to IV trials. They are generally described as follows:

Phase I

Small number of participants, normally between 6-10 healthy volunteers, or very sick patients for whom treatment options are lacking.

Phase I studies are designed to allow scientists and doctors to understand what effects a potential new medicine has in human subjects.

Phase II

Once the initial safety of the study drug has been confirmed in Phase I trials, Phase II trials are performed on larger groups of patients, generally 20-300 depending on the type of disease.

Phase II studies are designed to begin to evaluate the safety and efficacy of an investigational medicine in patients, and often used to determine if different dosages of the treatment have different effects.

Phase III

Carried out on large patient groups, 300–3,000 or more depending upon the disease being studied.

These studies are designed to confirm the safety and efficacy of an investigational medicine. Large numbers of patients are generally involved to adequately confirm benefit and safety.

Information obtained from Phase III studies is used to determine how the compound is best prescribed to patients in the future.

Phase IV

Phase IV studies take place after the medicine has received regulatory approval and are designed to provide broader efficacy and safety information about the new medicine in large numbers of patients, subpopulations of patients, and to compare and/or combine it with other available treatments.

These studies are designed to evaluate the long-term effects of the drug.