GCP

Good Clinical Practice

GCP is the international ethical and scientific quality standard for trials involving human participants. Its two purposes are inseparable: protecting the rights, safety, and wellbeing of participants — grounded in the Declaration of Helsinki — and ensuring the credibility of the data. A trial that harms participants is unethical; a trial with unreliable data has exposed participants to risk for no scientific return, which is also unethical.

The obligations divide across the parties. Sponsors are responsible for trial design, qualified oversight, safety reporting, and quality management. Investigators are responsible for the conduct at their site, informed consent, participant safety, and accurate records. Ethics committees and institutional review boards provide independent review and approval before a trial starts and continuing oversight while it runs.

ICH E6(R3), adopted in 2025, restructured the guideline around quality by design and proportionate, risk-based approaches. The intent is that quality is built into protocol design by identifying the factors critical to participant safety and data reliability, rather than pursued afterwards through exhaustive monitoring and source-data verification of everything. It is also written to accommodate decentralised trials, and data from a wider range of sources, which the earlier revisions handled awkwardly.

• —Two inseparable objectives: participant rights, safety, and wellbeing; and credible data.
• —Responsibilities split across sponsor, investigator, and ethics committee / IRB.
• —Ethics approval and informed consent must precede any trial-specific procedure.
• —E6(R3) (2025) centres quality by design and proportionate, risk-based approaches.
• —Critical-to-quality factors are identified in design, not chased afterwards through 100% SDV.
• —Accommodates decentralised trials and diverse data sources.

ICH E6(R3) Good Clinical Practice (2025); US: 21 CFR Parts 50, 54, 56, and 312; EU: Regulation (EU) No 536/2014 (Clinical Trials Regulation); the Declaration of Helsinki as the ethical foundation.