Clinical trials for medicines: Is a clinical trial authorisation (CTA) required?

Clinical trials - nurse counting tablets


Clinical trials in the UK are regulated by The Medicines for Human Use (Clinical Trials) Regulations 2004 (SI 1031) (external link) as amended. These regulations implement Directive 2001/20/EC ('The Clinical Trials Directive') (external link).

According to the Clinical Trials Directive, clinical trials of medicinal products in human subjects requires authorisation by the competent authority (MHRA in the UK) and a favourable opinion by an ethics committee. This authorisation is granted in the form of a clinical trial authorisation (CTA).

When is a clinical trial authorisation (CTA) required?
The regulations only apply to trials of medicinal products. These are substances or combinations of substances which either prevent or treat disease in human beings or are administered to human beings with a view to making a medical diagnosis or to restore, correct or modify physiological functions in humans. 

A clinical trial is an investigation in human subjects which is intended to discover or verify the clinical, pharmacological and/or other pharmacodynamic effects of one or more medicinal products, identify any adverse reactions or study the absorption, distribution, metabolism and excretion, with the object of ascertaining the safety and/or efficacy of those products. This definition includes pharmacokinetic studies.

Clinical studies involving only medical devices, food supplements or other non-medicinal therapies (such as surgical interventions) are not covered by the Directive. The regulations do not apply to non-interventional trials. In such trials, no additional diagnostic or monitoring procedure should be applied. Epidemiological methods should be used for the data analysis.

Is my study covered by the Directive?
To find out if your study is covered by the Directive or not, use the algorithm ‘Is it a clinical trial of a medicinal product?’ provided at the end of Volume 10 Notice to Applicants: Question & Answers - Clinical Trial Documents (external link).

Is it a clinical trial of a medicinal product?PDF file (opens in new window) (25Kb)

If, after using the algorithm, you are still unsure whether or not the clinical study is covered by the Directive then send an email to the clinical trial helpline ( marked ‘Scope - protocol review’ followed by the study title (short) in the subject line and request an opinion on the status of the study. A copy of the protocol should be provided with the request. Where possible, responses to such queries will be sent within seven days.

Please note that queries of this type will not be answered by telephone.

Is the product an investigational medicinal product (IMP) or a non-investigational medicinal product (NIMP)? 

The decision as to whether a product is an IMP or a NIMP depends on the product being used and the design of the study. Some mock examples have been produced in the setting of healthy volunteer studies to help in decision making. 

Mock examplesPDF file (opens in new window) (19Kb)

Page last modified: 02 April 2013