An introduction to Good Clinical Practice (GCP)

Clinical trials are an essential process for the development of new cancer therapies. All new medical treatments and procedures have to be thoroughly tested before being approved for routine use in the clinic.

All clinical trials are highly regulated to protect the safety of the people who take part, and the integrity of the information that the trials produce. Clinical trials are conducted in accordance with an international quality standard, called Good Clinical Practice (GCP), which is applicable in most countries around the world.

GCP is an ethical and scientific quality standard for the design, conduct, performance, monitoring, auditing, recording, analyses and reporting of clinical trials. GCP provides assurance to the public that the rights, safety, integrity and confidentiality of trial subjects are respected and protected, consistent with the principles that have their origin in the Declaration of Helsinki (internationally recognised ethical guidelines). In addition, GCP provides assurance that the clinical trial data and reported results are credible and accurate.

GCP became effective in 1997, but was not enforced by law at that time. The Medicines for Human Use (Clinical Trials) Regulations 2004 and the European Union (EU) Directive on Good Clinical Practice changed the world perspective, and compliance with GCP is now a legal obligation in the UK and Europe for all trials involving the investigation of medicinal products.

The EU Directives governing GCP and the conduct of clinical trials can be found here:


The main principles of GCP

There are 13 principles of GCP, as follows:

  1. Clinical trials should be conducted in accordance with the ethical principles that have their origin in the Declaration of Helsinki, and that are consistent with GCP and the applicable regulatory requirement(s).
  2. Before a trial is initiated, foreseeable risks and inconveniences should be weighed against the anticipated benefit for the individual trial subject and society. A trial should be initiated and continued only if the anticipated benefits justify the risks.
  3. The rights, safety, and wellbeing of the trial subjects are the most important considerations and should prevail over interests of science and society.
  4. The available nonclinical and clinical information on an investigational product should be adequate to support the proposed clinical trial.
  5. Clinical trials should be scientifically sound, and described in a clear, detailed protocol.
  6. A trial should be conducted in compliance with the protocol that has received prior institutional review board (IRB)/independent ethics committee (IEC) approval/favourable opinion.
  7. The medical care given to, and medical decisions made on behalf of, subjects should always be the responsibility of a qualified physician or, when appropriate, of a qualified dentist.
  8. Each individual involved in conducting a trial should be qualified by education, training, and experience to perform his or her respective task(s).
  9. Freely given informed consent should be obtained from every subject prior to clinical trial participation.
  10. All clinical trial information should be recorded, handled, and stored in a way that allows its accurate reporting, interpretation and verification.
  11. The confidentiality of records that could identify subjects should be protected, respecting the privacy and confidentiality rules in accordance with the applicable regulatory requirement(s).
  12. Investigational products should be manufactured, handled, and stored in accordance with applicable good manufacturing practice (GMP). They should be used in accordance with the approved protocol.
  13. Systems with procedures that assure the quality of every aspect of the trial should be implemented.


International Council for Harmonisation GCP

The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) brings together regulatory authorities and the pharmaceutical industry to discuss the scientific and technical aspects of registering drugs. ICH was established in 1990, and has gradually evolved to respond to the globalisation of drug development.

The aim of ICH is to achieve greater harmonisation and co-ordination of GCP worldwide to ensure the development of safe, effective, and high quality medicines. Regardless of where they are conducted, all clinical trials included in applications for marketing authorisations (product licences) in the EU must be conducted in accordance with ICH GCP.


Further reading

International Council for Harmonisation (ICH) Good Clinical Practice (GCP) guidelines (May 1996). Describe the responsibilities and expectations of all participants in the conduct of clinical trials, including investigators, monitors, sponsors and ethics committees.

Medicines and Healthcare products Regulatory Agency (MHRA) – good clinical practice: guidance and inspections (December 2014). Describes how to meet the good clinical practice standards for clinical trials and what to expect from an inspection.

The Medicines for Human Use (Clinical Trials) Regulations 2004. The UK legislation governing the conduct of clinical trials in the UK.