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What Really Happens During A Clinical Trial?

Clinical trials are vital for improving the health of the global population.


Dr. Beccy Corkill

Beccy is a custom content producer who holds a PhD in Biological Science, a Master’s in Parasites and Disease Vectors, and a Bachelor’s in Human Biology and Forensic Science.

Custom Content Manager

What really happens during a clinical trial. Vector art of woman with biomolecules and microscope on a purple background

Over the last century, the world has benefitted from countless health research breakthroughs and many advancements in medical knowledge. Just in the last few years, these have ranged from poop transplants and regenerating livers to lab-grown blood and a malaria vaccine. You name it, scientists have probably dissected and analyzed it with the aim to eradicate disease and improve the health of the global population.

In fact, just in the last few years, researchers have gained U.S. Food and Drug Administration (FDA) approval for a type 1 diabetes delay drug, gene therapy for adult hemophilia B, and of course the development of COVID-19 vaccinations. The development, approval, and distribution of these therapeutics are governed by many regulations, and it can take a lot of time, money, and effort to get them to those who need them throughout the world. 

Of course, none of these medical advances could have occurred without the help of countless volunteers around the world who take part in regulated clinical trials. 

You may have become familiar with clinical trials after flicking through the news channels, especially over the past few years. Despite this news coverage, many people may still be scratching their heads and wondering what clinical trials are and what it would be like to take part in one.  

Clinical trials are studies with human participants that help test medicines and vaccines that have the potential to prevent, detect, and treat diseases, and are an essential part of medical discoveries. These trials help us learn more about a study drug or vaccine, how it may work, and any side effects it may have. These regulated clinical trials ensure that new therapeutics and vaccines are backed by scientifically sound evidence and data. 

Have you ever wanted to take part in a scientific process? To help contribute to the development of life-saving discoveries? Or to participate in a trial for an illness you or your loved ones may have, but felt hesitant about as you did not know all the answers? 

Well, here we have gathered some common concerns and done a deep dive into the clinical trial process. 

Clinical trial locations 

Clinical trials can take place in a research center, medical institute, university, or hospital. The location will depend on the study itself. 

Any study-related medical care is provided by the study team, which consists of a principal investigator/study doctor (who is a healthcare professional responsible for the trial at the location) and other clinical study team members. 

The phases of clinical trials 

Clinical trials are often separated into four different phases.  

Phase one: Involves 20-100 volunteers to determine if the potential medicines or vaccines are safe and to work out the optimum dosage.

Phase two: Involves several hundred volunteers who have the condition/disease, to understand how well the potential medicine or vaccines may work for the condition being studied and the side effects that may occur. 

Phase three: Similar to phase two but on a larger scale (300-3,000 people) and can last between one and four years. 

Phase four: Involves several thousand participants with the condition to better understand the long-term safety and efficacy of approved medicines or vaccines over time.

Throughout all phases of clinical trials, there are regulations and guidelines that are followed to ensure the safety, well-being, and rights of the volunteers are always met. There are also many entities that monitor these trials, including but not limited to: the FDA, data and safety monitoring boards, institutional review boards, and independent ethics committees. 

Clinical trial monitoring 

Participant safety and quality data are essential in clinical trials. If the data are not accurate, or reliably collected and analyzed, then any resulting decisions could be wrong. Fortunately, the data collected (typically at trial locations) are continuously monitored, both by systems and by individuals such as site monitors. These monitors review clinical trial conduct activities based on a study monitoring plan, which can include a review of each facility’s physical space, systems, documentation processes, and storage. 

Monitoring requirements have been consistent for decades, but methods of monitoring continued to evolve during the COVID-19 pandemic to use access of data through systems for remote clinical monitoring, in addition to on-site monitoring visits more frequently.

This type of monitoring has been going on for decades but continued to evolve during the COVID-19 pandemic when remote clinical monitoring was implemented more frequently. 

Clinical trial participants 

Volunteers for clinical trials, known as participants, are critical to moving science forward. Their participation helps researchers and physicians find clinical answers and medical solutions for people around the world. 

Each clinical trial pursues an endpoint of safety and efficacy to benefit those who seek an intervention or treatment. If met, interventions and treatments can most broadly improve health outcomes when the participant data assessed fully reflects the impacted patient population.  

Ideally, clinical trial populations include people of all races, ethnicities, sexes, genders, ages, and abilities, from all walks of life, who meet the eligibility criteria of the study. As a medicine or vaccine may work differently from person to person, there is always a critical need for diverse participant populations to ensure we develop the safest and most effective products for the most people.

Randomized vs. controlled clinical trial 

Anyone that joins a clinical trial gets informed about the trial protocol through a document that explains the purpose and how the trials will be conducted (whether it will be randomized). This is known as the informed consent process.

In many clinical trials the “gold standard” is a randomized and placebo-controlled trial. A placebo is classified as an inactive medication. These trials involve the participant being randomly assigned to receive either the intervention being studied, a placebo, or standard care. Often, everyone in the study is “blind” to the treatment they are receiving, in order to avoid bias. 

Trials can be single-blind (where the researchers know but the participant does not know) or double-blind (neither the participants nor the researchers know). Some people may worry that they will be given a placebo as a comparison. In more recent times, the percentage of placebo trials is low and every clinical trial protocol is different. 

Cancer trials are a type of clinical trial that does not use placebo medication. This is called a controlled trial. This is when the participants will receive the study medicine or a “comparator”. Along with cancer trials, some studies compare the new drug with the current standard of care. In this type of study, researchers can learn more about the effectiveness and safety of the therapeutic, as they compare the experience of each set of volunteers.  

Whether a trial is single-blind, double-blind, placebo-controlled, or competitor-controlled, this information will always be discussed during the informed consent phase. This process also allows the participant to ask any questions they may have to the trial organizers. 

Clinical trial safety 

During a clinical trial, the safety and well-being of all participants are of the utmost importance, and so researchers are required to follow specific guidelines and regulatory requirements to protect this. Sometimes, there is a concern that the participant will undergo unknown medical procedures. However, a patient’s rights and consent are critical in clinical trials and participation is always voluntary. The risks are always explained at the start before the study takes place and participants are kept very informed throughout each phase. 

If the trial is not for you, people are always free to leave at any time or for any reason. However, it is recommended when doing so to inform the study doctor to ensure that it is done in the safest way possible. 

Clinical trial compensation

Time may be a concern for some people, as they may think it could be a big commitment. But it all depends on the trial: some trials offer reasonable financial compensation for the time and effort it takes. If compensation is applicable, it will be outlined in the consent document. 

What happens when a trial ends?  

After a trial, the data will be analyzed and decisions will be made on whether the potential new treatment continues onto the next phase or (if in the later phases) whether the investigational medication or vaccine will benefit the population it is being studied for. Often, the results of the trial are published in peer-reviewed scientific journals, on, and on the company’s website. 

If enough data from the trials support a safe and effective potential new medicine or vaccine, an application will then be submitted to regulatory authorities such as the FDA for review and potential approval for use by patients. This process often takes years.

The future of clinical trials 

The future of clinical trials is changing and there has been a significant amount of innovation that may have changed the traditional experience. The COVID-19 pandemic was a springboard for some of the more recent advances (such as remote monitoring) and really highlighted the importance of clinical trials to the general public. 

One very important aspect that organizations are working on is the diversity of the trial population and the accessibility of people to access clinical trials.  

Recently, one study successfully took clinical trials even further and conducted a computer model simulated clinical trial that tested two Alzheimer drugs, in a head-to-head study. The researchers called this a “virtual clinical trial”.

Increasingly, the healthcare community is collecting real-world data (RWD) and real-world evidence to support clinical trial designs. This data can be used to fill in knowledge gaps that scientists may have about how the medication is used in real-world medical settings. 

Overall, clinical trials are an important step and milestone in any medical advancement. There is always a need for volunteer participants in clinical trials, so if you want to contribute to the scientific community’s cry of “Eureka!” be sure to investigate the different opportunities.  

A summarized infographic version of this article is available here!

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