What are the Different Phases in Clinical Research?

What are the Different Phases in Clinical Research? 

If you have ever considered participating in a clinical trial, you may have heard that there are different phases in clinical trials. 

New medications, treatments and devices have to go through multiple phases in order to become approved. If you are wondering what the difference between each phase is and why it is important to understand before participating in clinical trials, you are in the right place! 

At TheClinResearcher we understand that clinical trials can seem confusing and daunting. We are here to change that by sharing useful information that can benefit you as you start participating in clinical trials! 

The Importance of Phases in Clinical Trials 

For starters, if you are considering joining a clinical trial, the phase will tell you how far along the trial is or how close it is to becoming approved. It might also give you insights into whether the trial is enrolling healthy participants or if you must have the target diagnosis. 

Clinical trials have to progress through phases starting at phase I, these trials are usually first in humans meaning that they have not been tested in people yet. The study will usually require you to be a healthy individual (although there are exceptions to this rule) in order to test that the medication is safe. 

That means that the earliest phase in theory will have the least amount of information regarding safety and effectiveness. As it progresses through the phases, the researchers will be able to compile more information and learn more about the medication. 

After phase I the medication will  progress all the way through to phase IV as it successfully completes each phase. 

By understanding the different phases you will have a greater understanding in regards to what the trial is attempting to show, and how much information is already known based on previous phases. 

It can also be beneficial to understand the difference in clinical trial phases as this can help you decide between multiple trials. 

Phase I Clinical Research Trials 

The first part of human trials are phase one trials. These trials are conducted at clinical research sites such as hospitals, private clinics, and universities. Since this is the first time that the drug or medication will be used by a human, these trials are done on healthy individuals. 

For phase one trials, people who wish to participate are screened for the study based on different parameters that might include or exclude them. This can include personal medical history, family history, as well as lab and other diagnostic results. There may be questionnaires, assessments, and other requirements involved. 

This step is done for every trial regardless of the phase they are in, in order to find a group of people who can participate in the trial with minimal variations in the results. However, for most phase one trials, the participants must be healthy. 

Phase I trials are concerned with the safety of a new medication or treatment and hence why it is tested in healthy participants. Once enough information is collected to show that it is safe in the first phase of the trial, it may proceed to the next phase. 

If you are interested in participating in clinical research and suffer from a health condition, you could potentially participate in trials that have already passed their first phase. 

Phase II trials focus on identifying the efficacy of a new drug. If it passed Phase I that means that it showed to be safe based on the standards set by the FDA or local regulatory agencies. 

The next step for a drug or medical device is to test for efficacy or to test if it works. The pharmaceutical company and its scientists have theorized on the mechanism and how it could potentially benefit patients but it has to pass the test. 

An example would be a new medication for blood pressure. This would be tested in animals and different biomarkers would be checked. If this passes specified standards it will be approved to proceed to human trials. Once it passes Phase I and there is enough data to show it is also safe in humans, Phase II will include patients who are hypertensive. As opposed to Phase I where the participants must not have health issues. Phase II requires that the participant has hypertension in order to see what results it has. Will it lower blood pressure for enough participants? Does it only work for a specific population? 

The pharmaceutical companies will recruit participants who have the issue or “indication” but will also need to meet other requirements in the inclusion and exclusion part of the protocol. If the participant has a health condition that could be aggravated by the drug, they would be disqualified from participating for example. Or the participant might be on a medication that can react to the new drug’s active ingredient which would also disqualify them. 

Once the participant has been screened for the study and meets all of the inclusion and exclusion criteria, they will be asked to proceed with the study. The participant will be instructed on what they should do moving forward concerning medication instructions, clinic visits and what to do if they need to report anything abnormal. 

These trials can last from weeks to years, and the time commitments can differ depending on the medication. The participant can decide to stop participating at any point or for any reason from any trial as it is always voluntary. 

Phase III Clinical Research Trials

Once enough data is collected from Phase II trials the drug will be approved to proceed into Phase III. 

This is the last phase before it is brought to market! Phase III is concerned with the difference between the new medication and other treatments that are already available. 

Oftentimes, Phase III trials will have participants take either a medication that is already available on the market or the new study medication. This is decided randomly known as randomization, and for the majority of trials will be blinded to the participant and study staff. Meaning that neither the participant or the doctors and nurses know what the subject is taking. 

This helps to prevent any type of bias or placebo effect that can interfere with the study. If there is a reason for needing to “unblind” the study staff and participants there is the ability to do so. This is done if there are any type of side effects or interactions that the subject might need treatment for. 

Phase III trials can also vary in length and also recruit people who have the disease process for which the medication was designed for. This data is used to compare, as well as provide additional data on the efficacy of the drug and to determine if it might be better or safer than the current standard of care. 

Phase IV Clinical Research Trials 

Once the medication has passed through Phase I, II and III, the drug is ready to be sold. The medication will be prescribed or sold over the counter. It takes the pharmaceutical companies years, lots of money and the combined efforts of participants and site staff to get these medications out to market. All of this with the hopes that it will improve patient lives and help prevent, cure or treat an existing condition. 

Even though drugs at this stage have been proven to be safe and effective. The FDA must still keep a close eye on any reported safety issues. The medication will be widely prescribed and if issues arise it can always be taken off the market or reevaluated.

To Wrap Up 

Knowing the difference between the different phases in clinical trials can be very beneficial when deciding between clinical trials. It can also be helpful to know the phase of the clinical trial you are interested in enrolling into so that you can make an informed decision. 

To learn more about participating in clinical trials, we highly recommend you download our free guide by signing up for our exclusive newsletter. Together we can raise awareness of clinical trials, and improve health outcomes for everyone!