A clinical trial is a research study or scientific experiment that examines the use of drugs or other interventions in treatment. It asks a specific question to try and find better ways of preventing, diagnosing, and treating certain conditions in pregnancy, childbirth, or infancy.
There are three different phases of clinical trials. The most “experimental” stage is Phase I. By the time a treatment reaches a phase III clinical trial, it has been studied well. When a phase III trial is conducted under an organizing group of experts, it may also be called a protocol.
The importance of research
Research is the only way of improving the success of treatments. Each time a trial shows an improvement with a new type of treatment, this new treatment can be used with more pregnant women or babies.
Phase I trials
In a Phase I clinical trial, a new drug is tested to see if it is safe to use in humans. This is because it has been tested in laboratory and animal studies, and shown some promise. The goal of a Phase I trial is not to cure the disease or condition, although researchers hope that the drug will be effective.
Phase I clinical trials usually involve normal, healthy volunteers. A small dose is given to 30 or fewer subjects. The dose is slowly increased during the trial until harmful side effects appear. This is called the maximum tolerated dose. The previous lower dose is then accepted to be a safe dose. This safe dose is used if the drug moves on for further study in Phase II clinical trials.
Benefits of phase I trials
A Phase I study can help doctors learn how new drugs are used in the body, and to determine the correct dose and dose interval.
Because the drug is new, the side effects may not be known. Side effects may be serious, and cause pain or discomfort.
Phase II trials
In Phase II, a drug is tested to see what effect it has on a specific condition. The trial also studies which types of conditions can be treated with the drug. The safe dose that was established in Phase I is tested on 30 to 100 participants.
Participating in a phase II trial
Phase II trials are offered to people whose condition has not been controlled by other treatments. It also depends on type of condition, the overall health of the patient, and the amount of therapy already received. A limited number of treatment centres offer Phase II trials.
Potential benefits of phase II trials
The drug may help some participants. The results may help others in the future.
There may be unexpected and serious side effects. The side effects may cause pain and discomfort.
Phase III trials
By the time a drug or therapy reaches a Phase III clinical trial, it has gone through Phase I and II trials and appears to work. The drug or intervention is now compared to the treatment current standard treatment or intevention. The goal is to find out which intervention is better. This might be measured by survival rates, side effects, or other outcomes. Participants are randomly assigned to receive one of the two interventions. The trial can involve 100 to 1000 people.
Participating in a phase III trial
Phase III trials are offered at certain treatment centres to patients entering care. The exact eligibility depends on the goals of the particular study.
Potential benefits of phase III trials
There is a good chance the drug will help participants. If the drug or intervention proves to be effective in Phase III trials, it may receive government approval to be used for this specific illness. As a result, the drug will eventually be widely available to help or cure many people.
There may be side effects, but these are known from Phase I and II. A strategy may be in place to help reduce the side effects.
Questions to ask about a clinical trial
- What is the purpose of the clinical trial?
- What is the phase of the clinical trial?
- What is involved in the treatment plan?
- What are the benefits of participating?
- What are the risks of participating?
- Is there any information about how other patients have responded to the same treatment?
- What are the side effects, both in the short- and long-term? How will the side effects be prevented or managed?
- Are any extra diagnostic tests required?
- What effect might this have on other family members?
What does informed consent to take part in research or a clinical trial involve?
You may be asked to decide whether or not to take part in a research study or a clinical trial. The person asking you to make this decision must make certain you have a full understanding of the purpose of study, the results expected, how the study works, any risks or benefits, and in the case of a clinical trial, the other treatments available. You may ask questions about the study and receive information about the results when the study is finished.
After explaining this, you will be asked to make a decision about taking part in the study. To give consent to take part, you will sign a consent form describing the research and the risks and benefits.
If you decide not to take part in a research study or clinical trial, you and your baby will continue to receive the same quality of care from the health care team and the hospital. If you do decide to take part in the study or trial, signing a consent form is not a contract. You can change your mind, withdraw your consent, and leave the research study or clinical trial at any time. If you decide to withdraw your consent, you and your baby will continue to receive the same quality of care from the health care team and the hospital.
How are new drugs developed?
Drug development usually takes a lot of time and research. It begins in the laboratory where a drug has shown to have some effect on a disease or condition in animals, for example. At this stage, it is called pre-clinical research.
After a drug has shown promise, it will be tested in a clinical trial with humans. Clinical trials move through various phases.
After each clinical trial, the researchers will write about their findings. They will describe the procedure, the participants, treatment results, side effects, and their understanding of the results. The researchers will send their report to a scientific journal. Other experts who are not connected to the study will read and analyze this report. This is called peer review. If these experts agree that the trial was of high quality, the report will be published.
After reading the report, other researchers in different cities and countries should be able to repeat similar trials to see if they get the same results. Larger and larger numbers of patients will participate.
After a number of trials that show its effectiveness, a drug or intervention is approved by a national regulatory body, such as Health Canada , the U.S. Food and Drug Administration, or the Medicines Control Agency in the United Kingdom . Usually, it is first approved for a very particular condition and situation. Later trials help pave the way for the drug to be approved for use with different conditions or age groups.
This long process shows why the discovery of “miracle cures” in science is so rare. Scientific discovery moves in small steps. Each of these steps involves a clinical trial that takes a great deal of time, effort, collaboration, and thought by many different researchers.
This scientific process is not always perfect – for example, some journals have higher standards than others – but it is the best way to make sure that a new treatment is safe and effective.