A clinical trial is a type of research study in which participants are assigned according to a pre-defined therapeutic strategy or plan (protocol) to receive a health-related intervention, such as a medicine, to investigate its effects on health outcomes, usually compared to another (or sometimes no) treatment.
Clinical trials are used:
- to evaluate clinical practices that do not fall within the approved practices of a country,
- to evaluate a new medicine (investigational medicinal product) or device,
- to generate data on the safety and efficacy of the intervention.
Clinical trials are conducted only after a regulatory authority approval and ethics committee review. They are conducted in clinical phases from I (Non-therapeutic, first-in-human), II (Exploratory), III (Confirmatory) to IV (Post-approval).
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To go in depth
Clinical Trials and Clinical Research: A Comprehensive Review
This online review comprehensively describes the critical elements of clinical research that include clinical trial phases, types, and designs of clinical trials, operations of trial, audit, and management, and ethical concerns.
- Venkataramana K, Vadakedath S. Clinical Trials and Clinical Research: A Comprehensive Review. Cureus 2023 Feb; 15(2): e35077
What the European law says
Previously, the terms clinical study and clinical trial were used synonymously. But it is necessary to underline that, from a legal point of view, these two terms have different meanings. To understand the difference between the two terms, refer to the to the definitions contained in the European Regulation No 536/2014 (art 2).
Clinical trial means a clinical study which fulfils any of the following conditions:
- the assignment of the subject to a particular therapeutic strategy is decided in advance and does not fall within normal clinical practice of the Member State concerned.
- the decision to prescribe the investigational medicinal products is taken together with the decision to include the subject in the clinical study or
- diagnostic or monitoring procedures in addition to normal clinical practice are applied to the subjects.
Any investigation in relation to humans intended:
- to discover or verify the clinical, pharmacological, or other pharmacodynamic effects of one or more medicinal products.
- to identify any adverse reactions to one or more medicinal products; or
- to study the absorption, distribution, metabolism, and excretion of one or more medicinal products, with the objective of ascertaining the safety and/or efficacy of those medicinal products.
- REGULATION (EU) No 536/2014 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 April 2014 on clinical trials on medicinal products for human use, and repealing Directive 2001/20/EC (art 2)
Clinical Study or a Clinical Trial?
The following video explains the differences between clinical study and clinical trial