How Clinical Trials Work and Why they are Important


Have you ever wondered how medication finds its way from a pharmaceutical company to your prescription bottle? Have you ever been curious about the process of testing, approving, and marketing medications? Every drug – from a basic pain reliever to a powerful anti-psychotic medication- must first undergo a series of clinical tests before it can be approved for use. Clinical trials are highly regulated by ethics boards which ensure that studies are conducted ethically and that patient safety remains a priority throughout the trial.  This article will outline the progression of clinical trials, from the inception of an idea, to the availability of a drug at your local pharmacy; a process that can take an average of 15 years.

What is a Clinical Trial?

A clinical trial adheres to a particular protocol and set of procedures in order to answer particular question (e.g. what is the effectiveness of drug X). A clinical trial essentially involves i) recruitment of participants that may potentially benefit from participation and that fit the criteria of a trial, ii) administration of the studied medication iii) collection and interpretation of the results for that medication (e.g. did it improve symptoms and was it more effective than placebo or the standard treatment?). These three steps are performed repeatedly in numerous trials until all important questions are answered.

Trials generally start small with only a few participants, and gradually grow to include a larger sample of participants. With each successive phase of trials, the question being asked evolves with the aim of learning new information. For instance, an initial trial for a novel hypertension (blood pressure) medication may ask ‘how effective is this medication in lowering blood pressure?’ As information is gathered and analyzed, the question may be modified to ‘how effective is this medication at lowering blood pressure when given with a medication for high cholesterol?’ An important aspect of conducting a clinical trial is to gather important information for how this drug will work in the real world.

A note on Ethics and Safety

Every aspect of clinical research (from the study design to the advertising and marketing associated with a drug) is highly regulated and monitored by the Institutional Review Board (IRB).The IRB consists of a committee of health professionals, researchers and members of the general public that reviews all research involving humans.  The IRB ensures that clinical trials are conducted in such a way that participants are protected ethically (e.g. they aren’t given a drug which has no potential for benefit) and physically (e.g. participants in clinical trials are regularly monitored by a physician and have 24 hour access to medical care should they need it).  Furthermore, health professionals and researchers involved in clinical trials are required to have completed training on Good Clinical Practice (GCP) which further emphasizes ethical considerations for clinical research.

  What are the Benefits of Clinical Trial Participation?

Clearly, a clinical trial cannot progress without the involvement of participants. A qualified candidate (i.e. someone who meets the inclusion/exclusion criteria for a particular study) may be introduced to a new medication for their condition. The possibility to alleviate or control symptoms is often a top ranking reason for study participation, particularly among individuals who are not benefiting from current treatments. By participating in a trial, a participant is provided with more healthcare options, and can become more active in their own well-being. Furthermore, study participation contributes to the advancement of medical research and the potential to help others who are not benefiting from current treatment options. Participation in clinical research today greatly benefits future generations.

Another benefit of trial participation is monetary compensation for the time and expenses incurred during trial participation. Study compensation is based on factors such as the duration of stay in the clinic, travel, and the frequency of follow up visits.

The Different Types of Clinical Trials

There are two major types of clinical trials: observational studies and interventional studies.  An observational study is one in which medication is typically not administered and the investigator simply observes a subject for an outcome measure such as elevation of blood pressure. An interventional study is one in which a subject is given a new medication to compare against an existing treatment, or no treatment at all (i.e. a placebo). This type of study looks to identify changes, if any, in a subject’s physical condition and health.

Clinical trials can additionally be differentiated into separate phases. Each of these phases is designed to answer a specific question. Listed below is a brief overview of the different phases:

Phase I Trial: Phase I trials investigate the initial stage or ‘the birth’ of a medication or treatment regimen. This stage marks the transition of a drug from animal testing to clinical testing (i.e. for therapeutic use in humans).  Phase I Trials tend to be fairly small in size, averaging between 20-100 participants. During Phase I, the dose-specific chemical and biological effects of the drug (including undesirable and adverse effects) are noted and participants are monitored at regular time intervals.

Phase II Trial:  Phase II trials commence after the completion of phase one trials. Phase II trials can last up to several years and involve hundreds of participants. Phase II trials test the effectiveness of a given drug at different dosages (which are determined based on Phase I results), and begin initial trials to gauge drug safety.

Phase III Trial: Phase III trials investigate the effectiveness and side effects of the investigational drug in comparison to the best available treatment (i.e. the ‘gold standard’). These trials can involve hundreds to thousands of participants over the duration of several years. This is an important phase as it provides pharmaceutical companies and regulatory bodies like Health Canada and the Food and Drug Administration (FDA) with additional safety information about a drug.

Phase IV Trial: Phase IV trials take place after a drug has been granted approval with the objective of monitoring safety and comparing the drug with other available treatments or investigating the effectiveness in adjunct (i.e. used at the same time) with other drugs. These trials are often called ‘after-market trials’ because the properties of the drug have already been studied, and the focus is on how they may be improved upon.

A Final Word

In summary, clinical trials are an integral part of our understanding of human well-being.  They provide reliable and valid procedures for investigating the effectiveness of drugs and have evolved the way we treat human disease. They have taken the guess work out of medication administration and provide a safe and monitored site for investigation.

We hope this article clears up any questions you may have regarding clinical trials. We find it of importance to inform you of the process of clinical trials so that you or a loved one can be more aware and make an informed decision about trial participation. You may simply be an interested reader, or you may be a person who suffers from a chronic medical condition. Either way, we hope this information has been beneficial. Should you have any questions, please do not hesitate to contact Canadian Centre for Clinical Trials at 289-597-0106.

Take care, be informed, and stay healthy!