What is a clinical trial? In short, clinical trials are where new medical research and people meet.

Clinical trials are studies in which new treatments (drugs, devices, or biologics) are tested using human subjects. Clinical trials can take many forms, but randomized, controlled trials (RCTs) are the gold standard for determining whether a treatment will be allowed to be widely applied to the general public.

Randomized and Controlled

In an RCT, the researchers running the study, usually referred to as “investigators,” are looking to compare two or more treatments to try to determine if one of them is effective. To do this, investigators recruit subjects and randomly assign an investigational treatment to each subject. This is the “randomized” element of an RCT.

Randomization is one of the most powerful bias-eliminating tools available to investigators. If randomization is done correctly, any subject-level characteristics that might affect the results of the study will be equally present across all treatment groups and will end up balancing each other out. Then, the only difference between the two groups should be the investigational treatments they receive. When everything else is equal, investigators can study the resulting data to draw conclusions about how the investigational treatments work compared to each other.

The other component of an RCT – “controlled” – is a way of creating a standard to which comparisons can be made within a study. In a controlled experiment, subjects are divided into two types of groups: the experimental group and the control group (there may be more than one experimental group, depending on the goals of the study). The experimental group contains the subjects who are receiving the investigational treatment. The control group receives either a different treatment, a placebo, no treatment, or in some cases something else, and serves as the standard to which the experimental group is compared. The presence of a control group is what makes a study “controlled.”

In well-designed RCTs, investigators use randomization and control to gain knowledge about whether a treatment works or not. It’s easier said than done, of course: RCTs are expensive and time-consuming. But they are also the best tool we have to determine with confidence whether any particular drug, device or biologic actually works.

Safety and Efficacy

Clinical trials are set up to evaluate two critical components of new treatments: safety and efficacy. Health authorities around the world ― like the FDA here in the United States ― require new treatments to be proven both safe and effective in large trials before being made available to the general population.

Only the most promising treatments ever make it to clinical trials. Before reaching the clinical phase, a potential new treatment must first be discovered through basic scientific research. Then, it must be shown to be effective and safe in cell and animal models. This phase of research is usually referred to as preclinical testing. If preclinical testing is successfully completed, investigators can begin clinical trials in humans. There are three phases of clinical trials prior to approval, and one phase after approval:

• Phase I – treats a small experimental group to find any major side effects and to determine the drug dosage to be used (safety).
• Phase II – focuses on the collection of data to see if the experimental treatment works in the population it aims to treat (efficacy).
• Phase III – continues to look at the experimental treatment's efficacy and expands the population and patient backgrounds to rigorously test for side effects. If they meet the safety and efficacy criteria set forth by health authorities, the experimental treatment can be approved.
• Phase IV – once approved, the long-term safety and efficacy of a treatment continue to be monitored in diverse patient populations. These trials can take years as side effects may not be visible in a short timeframe.

Clinical trials may take years to complete as they sometimes require data from hundreds or even thousands of subjects to prove safety and efficacy. Finding subjects who meet the specific requirements for a clinical trial and are also willing to participate is challenging because clinical trials sometimes require travel to and from the clinical site on multiple occasions.

Despite these challenges, clinical trials are necessary to ensure patients only receive the best and safest medical treatments. Clinical trial participation represents a unique opportunity to not only have access to experimental treatment, but also to advance research that brings life-changing interventions to market. Regardless of why a subject decides to enroll, clinical trial participants are the foundation of medical breakthroughs. Without them, the advancement of medicine would be nearly impossible.

Are you interested in joining a clinical trial? Visit www.clinicaltrials.gov to search for a trial that may be relevant to you. Talk to your doctor to see if taking part in a clinical trial is right for you. Entry into the study is dependent on meeting certain criteria as set by the study.  

Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6235704/

https://www.law.cornell.edu/cfr/text/21/314.126

https://www.nia.nih.gov/health/what-are-clinical-trials-and-studies