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Ethics

Clinical Studies (1st part)

Definition

A clinical trial is a medical research involving voluntary human beings. The aim is to develop a new treatment, to estimate its effectiveness and/or to show it is better than the best treatments for the pathology studied by an improvement in the chances for recovery, the quality of life or by a decrease in the harmful side effects.
In other words, the clinical trials (or clinical studies) are used to determine whether new medicines or treatments are safe and effective for a given pathology ( cancer for example). Tests in the laboratory and carried out on animals aiming at showing that the results are promising and free from all signs of harmful effects are the sine qua non condition for administering the new therapies to human beings.

 

Clinical trials are classified in four categories or phases

• Phase I Trials :
  The tentative treatment is administered to a small number of patients (10-12). Indeed, as the treatment has only been tested on animals, nobody knows how human beings will react to it . So, the research doctors carefully watch over the patients to intervene quickly if harmful side effects appear. The aim of clinical trials of phase 1 is to determine which is the best route of administration for the new treatment, its maximum allowable dose, and also the recommended dose for subsequent research which might be carried out with this treatment.
  The participation in these trials includes several risks, and within the context of cancer research, they will only be proposed to patients in a late stage of the pathology and for whom no current treatment has been effective. In some cases, the tentative treatment improves the patient's health condition. Within the context of medical research other than that concerning the treatment of cancer, the trial of phase I can be proposed to healthy voluntaries.
   
• Phase II Trials :
  Their aim is to test the effectiveness of the new treatment, to identify its optimum dose (in connexion with its effectiveness) and to control the side effects it causes.
  Usually, 15 to 20 patients take part in a study of phase II study.
  Within the context of the treatments of cancer, these trials target different kinds of cancers.
   
• Phase III Trials :
  Their aim is to test the effectiveness of the new treatment in comparison with that of the best known treatment , in other words, the reference treatment. These are large-scale studies because they have to be able to detect a possible difference, even a tiny one, between both treatments. Hundreds of thousands of voluntary patients are involved in these studies.
  Within the context of cancer, even a tiny difference is significant in the light of the number of persons suffering from it.
  Phase III Trials are very important for clinical research because their results will condition the daily clinical practice and therefore the accessibility to the new treatment.
   
• Phase IV Trials :
  These studies aim at controlling the effects of a medicine in the long term, measuring their effectiveness, the non toxicity in the long run and the possible appearance of rare side effects. New dosages and indications can also be tested.
  The number of patients taking part in these trials is variable.

How does a clinical trial work ?

The doctors and the researchers who carry out a clinical study follow a therapeutic plan or "protocol".
These protocols and their degree of complexity can be devised differently from one study to the next.
So, it is very important for the patients taking part in a clinical study to understand its plan and also its aim. The referring physicians are ready to answer the questions asked by the patients.
In the Phase III Trials aiming at comparing two different treatments administered to two groups of patients suffering from the same pathology, the patients belonging to the group known as "control" receive the reference treatment and are followed as carefully as those who belong to the group receiving the new one.
Much more rarely, if there is no reference treatment, the "control" group does not receive any active treatment (placebo).
The designation of the patients in both groups is achieved by a technique called "randomisation". This technique guarantees that both groups are really comparable. Usually, this procedure is computerised, which guarantees the scientific validity of the study.
The treatment attributed to the patient has to bring him an advantage. If not, the doctor can decide to remove him from the study and propose him another treatment. At any time, the patient can also decide to leave a clinical study, without any change in the quality of the care lavished on him.
The results of the study are regularly analysed during a trial. The trial can be interrupted if unexpected or unacceptable side effects appear or if the superiority of the new treatment is earlier than expected demonstrated. If so, the new treatment will replace the reference one.

2nd Part : click here
• Importance of clinical studies
• What is important to ask ?
• Protection of the patient
• Links with other web sites