What is a clinical trial?

A clinical trial is a carefully designed and executed medical research study for people who volunteer to receive an experimental drug or medical device under controlled circumstances for a specific period of time. The purpose of a clinical trial is to find solutions for the prevention and treatment of various medical conditions. Some trials accept volunteers who exhibit symptoms of a disease that is being studied, while other trials accept healthy volunteers. Clinical trials are usually sponsored by leading pharmaceutical and biotechnology companies and executed by clinical research organisations like Vx Pharma.

Types of clinical trials

The research goals of the following six main types of clinical trials are:

Bioequivalence trials—to compare two drugs with different trademarks to verify that they work in the body in identical ways and have equal activity.

Treatment trials—to gather information about the efficacy and risks of experimental drugs or medical devices, or to compare experimental therapies with existing ones to decide which is the best treatment for a particular condition;

Screening trials—to use imaging, laboratory or genetic tests to identify a disease before symptoms occur;

Diagnostic trials—to evaluate new tests that could identify a disease in its early stages; usually people must show symptoms to qualify for participation;

Prevention trials—to determine if positive lifestyle changes, like a more nutritional diet, or vitamins and vaccines could reduce the risk of illness or prevent the recurrence of a disease;

Quality of life trials—to find ways of improving life for sufferers of chronic health problems or life-threatening diseases;

Clinical trial phases

During a clinical trial a new drug or medical device can go through the following four distinct phases:

  • Phase 1—evaluated in a small group of often healthy people (20 to 80) to check its safety and side effects and to find the correct drug dosage;
  • Phase 2—evaluated in a bigger group of people (100 to 300) over a longer period to check if it is effective and safe;
  • Phase 3—evaluated in a large group of people (up to 3,000) and comparing it to a placebo or standard treatment to compare its safety and efficacy, after which medical regulatory bodies such as the U.S. Food and Drug Administration (FDA) will approve it if the results are positive;
  • Phase 4—takes place after regulatory approval to monitor safety and efficacy in large, diverse populations over a relatively long period of time.

Bioequivalence trials

Generic drugs are more affordable copies of innovator drugs. All generic drugs are required to undergo tests to demonstrate that they work in the same way and have the same effect as the innovator drug (i.e. bioequivalent). These are called bioequivalence trials and are performed in healthy volunteers only.