Definition:
A clinical trial is a medical term for specific type of research study which primary objective is to test new or different types of medical approaches, like new or different drugs, medical devices or treatments, in preventing, diagnosing and curing disease in human.
Who sponsors clinical trials?
Clinical trials are performed nearly in every country in the world; they are sponsored by organizations (e.g. medical institutions, pharmaceutical companies, foundations) or individuals, such as physicians, in which participation of patients or healthy persons in trials is exclusively voluntary.
What is the purpose of clinical trials and why are they important?
The main goal of clinical trial is to help doctors and healthcare professionals find out if tested medical approaches are safe and better than treatment options already available, and if they are ready for wider use in general population. Each study answers some scientific questions and tries to find better ways to prevent, diagnose, or treat a disease, often including the use of new kind of medicines or treatments.
How the creation process of the new medicine looks like?
Development of new medicine or therapy is very difficult, expensive and long-lasting process, usually taking more than 10-15 years, and only few of them (from several thousands in the beginning of the process) complete development successfully and come to the market as a new, valuable product.
Creation process can be divided into 3 steps. Everything usually starts within the laboratory environment, for example synthesis of new molecule, then proceeds with pre-clinical studies in vitro and in vivo which means laboratory testing and trials on animal population. Only after this phase proves results are satisfactory and acceptable from the medical point of view, development can proceed with final step - clinical studies, i.e. testing on human. This step is a milestone and represents the main and the most significant part of new drug creation. As it was mentioned, only a minimum number of products complete all these steps successfully and finally become suitable for use in general population.
What happens in a clinical trial?
Clinical trials are done to test whether new products are safe and efficient against disease/condition. Study products are tested to see how they compare to standard treatments or to no treatment if there is presently no treatment available.
Usually, study participants are randomized into treatment groups and many studies require that neither the patient nor the doctor know whether the patient is receiving the study treatment, the standard treatment, or a placebo (an inactive substance that exactly looks like the drug being tested, but has no activity). This kind of study design is often required because of objectivity of results obtained and it is called „double blind“ study, but if it is necessary from any reason, investigator could easily find out what kind of treatment patient is receiving and act properly.
What are the phases of clinical trials?
As a final and cardinal step in procreation of new product, clinical trials are recognized as the best, the safest and the most comprehensive scientific way how to test the new medicines today. Studies are done in phases to gain different kinds of information. From their very beginning to the end, clinical trials are exceptionally complex and rigorously controlled processes divided in 4 different phases (I to IV).
Phase I:
In Phase I clinical trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time. The study is designed to determine what happens to the drug in the human body - how it is absorbed, metabolized, and excreted. With primary goal of safety evaluation, determination of safe dosage range, investigators also identify side effects of new product. Typically, Phase I is done in small number of healthy male volunteers who are usually paid for participating in the study, but could be done in voluntary patients also. This first phase of testing usually takes a few months.
Phase II:
Once a drug has been shown to be safe in the Phase I trials, it must be tested for efficacy. In Phase II clinical trials, the study drug or treatment is given to a larger group of people (100-300) who have the disease or condition that the product potentially could treat, to see if it is effective and to further evaluate its safety. Phase II clinical trials also determine which dosage of the drug being tested has the best risk – benefit ratio. This dosage will than be tested in phase III. The second phase of testing may last from several months to year or two, and only if the Phase II trials indicate that the drug may be effective, and the risks are considered acceptable, the drug moves to Phase III.
PhaseIII:
In Phase III studies (typically the longest phase, sometimes few years), the study drug or treatment is given to large groups of people with the related disease (1,000-3,000 or more) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely. If Phase III is completed with success, new product is ready to be approved on the market and ready to be given to general population for a certain indication.
Phase IV:
Phase IV studies – they are conducted after a product is already approved and on the market - collect additional information, including the drug's or treatment's long-term risks, benefits, and optimal use.
How is it performed?
Every clinical trial has unique protocol (study plan) on which it is based, widely differing in many ways, but some steps or procedures in clinical trial management listed hereafter, are common for all clinical trials.
Entering a clinical trial
If you are undergoing treatment or are about to undergo treatment for a medical condition, you may be asked if you would like to be part of a clinical trial. You might also be interested in finding out what trials are taking place so you can volunteer to be part of one.
If you do find a trial suitable for you, your next step should be to discuss it with your doctor to see if you can be referred.
Giving consent
You cannot be entered into a clinical trial without your informed consent. If you are asked to take part in a trial you are free to say yes or no. For children and those under 18, a parent or guardian also has to give consent for them to take part in a trial.
The doctor who is organizing your treatment will usually talk to you about being involved and should explain all of the risks and the possible benefits.
Even if you want to be involved in a clinical trial, you may not be able to. The rules (protocol) for clinical trials are usually very specific about who is suitable. If you do not meet the criteria laid down in the protocol then you cannot be involved. Some trials seek participants with certain illnesses and conditions; others need healthy participants, or participants of a certain age.
The researchers conducting the trial must explain it to you and give you written information to take away. They should explain the aim of the trial, the treatments that are being tested, the possible benefits and any risks involved and how taking part in the trial will affect you.
You should be completely happy with the trial before you give your consent and be confident that you have been given all the information you need. This may mean taking some time to think about it and talk it over with family or friends before you make a decision. You should be given the time and space to do this.
If you do decide to take part you will be asked to sign a form to say that you are agreeing to take part in a clinical trial and have understood what that will involve. This is called giving your 'informed consent'.
Medical tests
When you agree to join a trial you may need to undergo some medical tests (usually blood tests) to see if you are eligible to join and be given the treatment. This will allow the researchers to know more about your health before you start with treatment, so that at the end of the trial they can tell whether there has been any improvement.
During the trial you may have more tests to see whether the treatment is working. This may involve more visits than normal to your place of treatment, or it may be possible for the tests to be carried out as part of your routine care.
Leaving a clinical trial
You and/or your doctor may decide that you should stop taking part in a trial if your condition is getting worse or the treatment is not helping you.
You can also choose to leave at any point in a trial without giving a reason and without it affecting the level of care you receive.
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