At the start of any new drug or vaccine lies an understanding of a disease, the identification of a target (therapeutic or vaccine) and a selection of the most active substances to provide treatment, relief or prevention. It takes two to four years of work to prepare a candidate drug or vaccine for development.
What is a clinical trial?
A clinical trial (also called clinical study) is designed to verify the efficacy and safety of a compound for use by human beings. It takes place after in vitro and animal studies (preclinical testing) have proved satisfactory. The compound, also called investigational product, is compared either to a placebo (a substance with no pharmacological activity) or to existing treatments, to determine whether it is more or less effective. The clinical trial determines the effective dose regimen, possible toxicity and the nature and frequency of adverse events it may cause.
Why are clinical trials necessary?
Clinical trials are a mandatory part of the procedure leading to approval of a drug for marketing. Before new treatments can be made available to all potential patients, they must be deemed effective and well tolerated. Clinical trials are used to validate new treatments but also to define the patient categories for which they are most effective. Finally, clinical trials help to gain a better understanding of the characteristics of a disease. Clinical trials are a mandatory part of the procedure leading to approval of a drug for marketing.
What are the criteria for the decision to launch a clinical study?
After identification of a compound under research, it is evaluated in vitro and then on animals. These steps provide a preliminary assessment of tolerance and therapeutic value. If all the data is satisfactory, the next step is to consider tests involving human beings.
The pharmaceutical manufacturer then submits a request to an Independent Ethics Committee (IEC) or Institutional Review Board (IRB), a completely independent body whose mission is to scrutinise the test procedures and protocol. The committee’s decision is based in particular on the pertinence of the project and the protection afforded to participants. The clinical trial may proceed only once it has been approved by the committee, which also follows regularly the progress of the trial to ensure continuity in the safety and welfare of the participants.
What are the risks for the patients?
All clinical trials run according to the Principles of Good Clinical Practice (GCP) are under the supervision of the above mentioned ethics committees whose mission is to ensure the safety and welfare of study participants. Clinical trials can only be conducted if all possible precautions have been taken to protect patient safety. Furthermore, the investigational drug is only tested if there is a real possibility of therapeutic benefit that needs to be evaluated. Participation in a clinical trial may give a patient the opportunity, especially when there are no existing treatments or they are ineffective or poorly tolerated, to benefit from innovative treatment.
The potential adverse events are part of the information given by the physician to patients invited to participate in a trial. Patients are given time to reflect. In the event that a patient wishes to enter a trial, he or she signs a free and informed consent form stating that relevant information on the study, its procedures, risks and constraints have been made known to him or her.
Biological, medical and clinical supervision of patients throughout the study ensure the highest degree of protection. Patients may decide at any time to withdraw from the trial.