Clinical Trials
Clinical studies (clinical trials) are conducted in order to gain advanced knowledge enhancing the quality of medical care and the efficacy and safety of drug products.
Recommendations for physicians concerning biomedical investigations on human subjects were specified in 1964 by the Declaration of Helsinki which is periodically revised.
The main objective of a clinical trial is to determine whether the use of a drug product or a medical procedure leads to the improvement of treatment outcomes and/or to the development of adverse events as compared to another therapy.
In order to refine the quality of data, supposed to be obtained, clinical trials must be randomized (i.e. study subjects are assigned to arms in a random manner). The main reason for randomization is to exclude systemic errors of a study.
The Study Protocol is the document which describes the trial’s scope, objectives, design, applied statistical methods and the organization of trial.
PHASES OF CLINICAL TRIAL
Phase I serves for the determination of a safe dose of drug product.
The main objective of Phase II is to study the drug effect on a human body, including the drug impact in the case of an increased dose, as well as to assess the safety, pathophysiological effects and, to some extent, the efficacy.
Studies of Phase III are conducted on a large sample size of subjects because the main task of this stage is to prove statistically the therapeutic effect of an investigational drug product.
Phase IV of trial is conducted in order to monitor the safety of drug product.
In the course of post-marketing studies, the manufacturer obtains additional information on the quality, safety and efficacy of the drug product when it is administered to a large number of patients, is used in cases of different pathologies and/or is interacting with concomitant drug products.