What are Clinical Trials?
Have you ever wondered how medication is developed and made available to the public? Every medication undergoes the same step-by-step process: a series of clinical testing to ensure safety and effectiveness for those in need.
A clinical trial is a medical study conducted to research and answer questions about medications, and to discover new treatments to improve and/or prevent medical conditions. Clinical trials are used to determine the safety and efficacy of new drugs and treatments. Carefully conducted clinical trials are the most effective and time-efficient way of finding treatments that work.
Clinical Trial Phases
Prior to entering study phases, all clinical trials must undergo a process of lab testing, animal testing, and testing in a small group of volunteers. Subsequently, clinical trials proceed through a series of steps, also known as phases. Each phase is designed to answer a separate research question:
Phase I Trials: How does the human body react to the drug?
These are the earliest trials in the life of a new drug or treatment, and are usually made up of 20-80 patients who are paid for participation. This phase determines the effects and tolerability of a drug on the human body. The effects of a drug are observed and recorded from the time it is taken until it leaves the body. This phase also examines the side effects of taking different quantities of a given drug. A high percentage of drugs (approximately 70%) are passed on to the next phase.
Phase II Trials: How effective is the drug?
Phase II can last from several months to several years, and can involve as many as 300 participants. Majority of phase II studies are randomized and double-blind, meaning that neither patients nor researchers are aware of who has received the experimental drug and who has received a “placebo” (a substitute with no effects). This phase compares different doses of the experimental drug in order to determine its effectiveness. The findings are then provided to pharmaceutical companies, the Food and Drug Administration (FDA), and Health Canada for evaluation.
Phase III Trials: Is this new drug better than existing drugs?
These trials compare the experimental drug to the best treatment available at the time of investigation. This phase can last up to several years and involve hundreds to thousands of participants. Out of all of the drugs that are used in the study initially, 70-90% are deemed successful upon completion of phase III. Following this phase, pharmaceutical companies, FDA, and Health Canada are provided with additional safety information on the drug.
Phase IV Trials: What is the best dosage or combination of the drug? How does it affect patients’ lifestyles?
Phase IV trials are carried out after the experimental drug has been approved and given a license. These trials provide pharmaceutical companies with a closer look at the new drug in comparison to other available treatments, or at a combination of the new drug with existing ones. Phase IV also evaluates the effects of the new drug on a patient’s lifestyle. Guidelines for drug use are established at this stage.