Types and Phases of Clinical Trials

Introduction to Clinical Trials

One of the most important medical tools at the disposal of researchers is that of the clinical trial.

Its purpose is to advance our understanding of medicine and improve the quality of life for patients and the general population alike. 

Clinical trials are not only used to find new disease treatments but also offer benefits such as enabling researchers to find out what new methods for disease detection and diagnosis may help reduce the likelihood of disease development.

Types of Clinical Trials

When referring to medical, or clinical trials, we refer to two main types – interventional or observational.

The purpose of interventional trials is to find out more about a particular treatment, or treatment as it is referred to here.

The team conducting the research will split the trial participants into various treatment groups to ascertain differences between the groups.

Observational studies, on the other hand, aim to understand the effects of different situations on the participants. Those taking part are not split into different treatment groups.

The research team observes those taking part but does not influence what treatments people have.

Within these two different types of categories, there are varying types of trails. Let’s take a look at the common types.

1.  Pilot Studies and Feasibility Studies

These are essentially smaller versions of the main trial.

Pilot studies are actual smaller versions of the main study. This basically means that it’s purpose is to test the different components of the test but on a smaller scale.

Occasionally, results from the pilot study are included in the results of the main study.

The purpose of feasibility trials is exactly that – to figure out whether it is in fact feasible to undertake the main trial.

The main research question is not asked. Instead, the metainformation is sought after such as how long the study would take and whether there would be patients and doctors who are interested in taking part.

2. Treatment Trials

Probably the most familiar out of the list, treatment trials are conducted in phases.

The earlier phases, or stages, aim to determine the safety of a new treatment and rule out certain side effects that would be too harmful to the general public.

Later phases try to find out whether the proposed new treatment is more effective than the current treatment.

3.  Case-Control Studies

For case-control studies, the researchers gather a group of participants who have the disease (cases) and another group who don’t (controls).

Participants are then looked at to determine whether participants were exposed to certain risk factors.

The different groups are normalized in the sense that participants with similar age, gender, and other predetermined factors are used.

While case-control studies may be cheaper than longer-term cohort studies, the results are less reliable due to incorrect participant reporting as well as the ease at which correlation can be confused for causation.

4.  Prevention Trials

In terms of cancer, this trial looks at whether a particular treatment can indeed help prevent the onset of cancer. Partaking participants do not have cancer.

The target group is the general population or those who have an increased risk for developing cancer such as those with certain genetic predispositions.

5. Screening trials

These trials aim to improve the accuracy of pre-cancer screening where early signs of cancer are picked up on so that prevention or treatment measures can be taken at an earlier, and therefore more advantageous, time.

Researchers may plan screening trials to determine whether new trials are reliable enough to detect particular types of cancer.

Phases of a Clinical Trial

A clinical trial is only undertaken when there is good reason to believe that a new test or treatment may improve the care of patients.

By the time a treatment reaches this stage, it has already undergone a preclinical research phase which is not done on humans.

The main purpose of clinical trials is to test their efficacy and safety in humans.

Here are the 4 phases of a clinical trial.

Phases 1

Phase 1 is the first stage and involves a small group of healthy people or sometimes patients. 

The goal here is to ascertain how the new treatment is processed in the body and the various associated effects. Phase 1 trials are mainly aimed at finding out the safety of the drug.

If the medication acts differently to what was expected, then the researchers will normally undertake additional preclinical research.

Phase 2

Phase 2 trials aim to:

• test the new drug in a larger group of people to better measure the safety and side effects
• to see if the drug has a positive effect on patients and to better understand the best dosage required to treat the illness while exhibiting the fewest side effects.

Phase 3

Phase 3 trials are large and may include hundreds, or sometimes many thousands, of patients.

Phase III clinical trials compare the safety and effectiveness of the newer treatment with the current standard treatment to ascertain how well the drug works. Phase 3 trials also focus on finding out any possible side effects or risks.

The goal here is to better understand short-lived and longer-lasting side effects and safety in a larger percentage of the target population.

Useful insight can also be elucidated about drug interaction on a larger scale at this stage of clinical trials.

Phase 4

Phase 4 trials are done after a new drug has been shown to work and has been given a licence.

These studies may involve thousands of people and are done to monitor long term effects and effectiveness when a drug is used more widely. It also aims at finding any possible rare side effects. 

Summary

There are a various different medical trials.

The type of medical trial chosen depends on the requirement and aim of those conducting the research to best understand whether their new treatment will be beneficial in finding a better treatment.

Apply for a Medical Trial

By now, we hope you have a better idea about what clinical trials do.

Are you interested in taking part in a clinical trial? 

Apply at Spoke Research. We specialize in Inflammatory Bowel Disease research and trials.

We study new treatments, conduct tests and evaluate their effects on human health.

We have a professional team consisting of a gastroenterologist, a medical doctor, and an experienced G.I.T. nurse.

If you’d like to participate in our clinical research as a patient, please apply to join a medical trial.