Things to know about clinical trials
What is a clinical trial?
Clinical trials are medical research projects on human subjects with the objective of assessing candidate medicinal substances in terms of general properties, efficacy, and untoward effects. Obviously, clinical trials, i.e. human exposure to the test substance, can only commence after a strictly regulated laboratory and animal experimental phase.
The objective of clinical trials is the advancement of pharmacological therapy, the development of ever more efficacious and safer drugs.
Clinical trials can be categorized from several aspects, one of which is as follows:
* Phase I clinical trial: usually carried out on healthy volunteers, this phase evaluates the test substance's tolerability and relative harmlessness.
* Phase II clinical trial: the test substance is administered to a carefully selected few patients of the target disease for the first time. This phase is aimed at calibrating the right dosage.
* Phase III clinical trial: involving an extended number of patients, this phase is about finding further evidence that the test substance is safe to use. The trial is often a comparison study with commercially available drugs already in everyday use for treating the target disease.
* Phase IV clinical trial: testing drugs already in commercial circulation, phase IV further assesses risk to benefit ratios, dosage refinements, and detects rare side effects.
It is evident from the definitions above that only phase I is fully experimental, with greater and greater emphasis placed on disease therapy along phases II to IV.
What makes an eligible subject for a clinical trial?
One of the governing principles of clinical trial participation is voluntariness.
Generally, who can participate in what kind of clinical trials is controlled by law. In addition, each clinical trial protocol will include a detailed set of inclusion/exclusion criteria to define who can participate.
The inclusion criteria are a list of conditions which must be satisfied if the candidate subject is to be eligible for participation.
Exclusion criteria are conditions in the presence of which the candidate subject cannot participate in the trial. Such conditions include e.g. age, type or severity of disease, previous therapy or concomitant diseases, etc.
Legal regulations and inclusion/exclusion criteria serve two important purposes.
One is to guarantee that only scientifically prudent research is carried out, leading to exact and reliable answers to the scientific questions raised.
The other is to guarantee maximum safety for participants of all clinical trials, and even to offer them medical benefit over phases II to IV.
Trial subject protection
Clinical trials are carried out in accordance with strictly defined, ethical committee approved, and regulatory authority permitted trial protocols. Prior to trial start, the investigating physician informs the subject about the trial and answers his/her questions. The information given is also found in a written Subject Information Document handed over to each subject. Subsequently, the signing of the Informed Consent can take place.
A copy of both the Subject Information Document and the Informed Consent must be given to the trial subject.
During or after closure of the trial, results are published at scientific conferences and in the medical literature. Identities and other personal details of trial participants can only be disclosed to a closed circle of persons specifically authorized by privacy law. Personal and research data are separated in the earliest phase of data analysis. That way, data analysis staff are not informed about trial subjects' personal details and they have no way of disclosing such information in their reports or other public communication.
