Clinical trials
Clinical trials are medical research studies in human subjects. Their aim is to investigate a medical, surgical or behavioral intervention and determine its safety and efficacy.
Additionally, clinical trials are often used to determine if a new treatment is more effective and/or has fewer side effects than established treatments. Clinical trials also explore ways to find diseases early, potentially even before the symptoms are present. Clinical trials can investigate how to improve quality of life for people living with chronic and life-threatening conditions for example by managing pain or symptoms. They may also consider the role of caregivers, healthcare staff and support groups in disease management.
Clinical trials involve multiple stages of testing. Before being approved for clinical trials in humans, researchers conduct animal and laboratory tests to consider the potential safety and efficacy of the intervention. If these pre-clinical studies show promising results they may be approved to be extrapolated to clinical trials in humans. Over four stages of testing to find the appropriate dosage and discover side effects. The four stages are as follows.
Phase I trials test a treatment on a small group of often healthy people, generally 20-80 participants, to determine its safety, side effects and set the correct drug dosage. The emphasis of this phase is on the safety of the treatment.
Phase II trials include a larger trial population of 100 to 300 people. The focus of this stage is on the effectiveness of the treatment. The aim of this phase is to obtain preliminary data on whether the treatment works in people suffering from a disease or condition. Safety and side effects continue to be studied at this stage.
Phase III trials further study safety and effectiveness but across different populations, dosages, and combinations with other treatments. The study population can range from hundreds to 3,000 people. If the findings are positive and the regulatory board agrees, it will approve the experimental treatment.
Phase IV trials take place after regulatory board approval of the treatment. A treatment’s effectiveness and safety are studied in large, diverse populations. It must be taken into consideration that the side effects of a drug or treatment may only become evident after a long delay. The FDA generally requires Phase I, II, and III trials to be completed before approving a treatment.