ICH E6 GCP Guidelines: Good Clinical Practice Requirements
ICH E6(R2), the Good Clinical Practice guideline, establishes the international ethical and scientific quality standard for designing, conducting, recording, and reporting clinical trials involving human participants, defining responsibilities for investigators, sponsors, and IRBs/IECs while ensuring participant protection, data integrity, and regulatory compliance.
ICH E6 is the single most important guideline governing clinical trial conduct worldwide. Originally adopted at ICH Step 4 in June 1996 as E6(R1), the current version E6(R2) was adopted at ICH Step 4 in November 2016, adding an Addendum that introduced risk-based approaches to clinical trial quality management. ICH E6(R3), a comprehensive revision currently in development (Step 2b draft released in May 2023), will further modernize GCP for decentralized trials and digital data sources, but E6(R2) remains the operative standard in 2026.
GCP compliance is not optional. It is a legal requirement enforced through FDA regulations (21 CFR Parts 50, 56, 312), EU Clinical Trials Regulation (EU) No 536/2014, and equivalent regulations across ICH member regions. Clinical data generated without GCP compliance is unacceptable for regulatory submissions.
In this guide, you'll learn:
- The 13 fundamental principles of ICH E6 GCP
- Investigator responsibilities for trial conduct and participant protection
- Sponsor responsibilities for trial oversight and quality management
- IRB/IEC requirements and the ethical review process
- Essential documents for clinical trial conduct
- Data integrity requirements including electronic records considerations
- The risk-based approach to quality management introduced in E6(R2)
The 13 Principles of ICH E6 GCP
ICH E6(R2) Section 2 defines 13 principles that form the ethical and scientific foundation for all clinical trial activities. These principles are not guidelines — they are requirements that must be satisfied for any clinical trial:
| # | Principle | Core Requirement |
|---|---|---|
| 1 | Ethical conduct | Clinical trials should be conducted in accordance with the ethical principles from the Declaration of Helsinki and consistent with GCP and applicable regulatory requirements |
| 2 | Risk-benefit assessment | Before a trial is initiated, foreseeable risks and inconveniences should be weighed against anticipated benefit; a trial should be initiated only if anticipated benefits justify the risks |
| 3 | Participant rights | Rights, safety, and well-being of trial subjects are the most important considerations and should prevail over interests of science and society |
| 4 | Nonclinical and clinical justification | Available nonclinical and clinical information should be adequate to support the proposed clinical trial |
| 5 | Scientific soundness | Clinical trials should be scientifically sound and described in clear, detailed protocols |
| 6 | Protocol compliance | A trial should be conducted in compliance with the protocol that has received prior IRB/IEC approval |
| 7 | Medical care | Medical care and medical decisions should be the responsibility of a qualified physician (or dentist) |
| 8 | Qualified personnel | Each individual involved in conducting a trial should be qualified by education, training, and experience |
| 9 | Informed consent | Freely given informed consent should be obtained from every subject prior to clinical trial participation |
| 10 | Recording and reporting | All clinical trial information should be recorded, handled, and stored in a way that allows accurate reporting, interpretation, and verification |
| 11 | Confidentiality | Confidentiality of records that could identify subjects should be protected |
| 12 | Manufacturing standards | Investigational products should be manufactured, handled, and stored in accordance with applicable GMP, and used in accordance with the approved protocol |
| 13 | Quality systems | Systems with procedures that assure the quality of every aspect of the trial should be implemented |
Investigator Responsibilities
ICH E6(R2) Sections 4.1 through 4.13 define the investigator's obligations. The investigator (or principal investigator for multi-site studies) bears personal responsibility for trial conduct at the clinical site.
Qualifications and Resources
| Requirement | ICH E6(R2) Section | Specifics |
|---|---|---|
| Qualifications | 4.1 | Qualified by education, training, and experience; must provide evidence (CV, credentials) |
| Adequate resources | 4.2 | Sufficient time, qualified staff, facilities, and equipment for the duration of the trial |
| Medical care | 4.3 | Qualified physician responsible for all trial-related medical decisions |
| Sub-investigators | 4.1.2 | Must maintain a list of appropriately qualified sub-investigators and trial staff |
Informed Consent
ICH E6(R2) Section 4.8 establishes detailed informed consent requirements:
| Element | Requirement |
|---|---|
| Language | Non-technical language that the participant can understand |
| Information provided | Purpose, duration, procedures, risks, benefits, alternatives, compensation, confidentiality, voluntary nature, right to withdraw |
| Process | Adequate time for consideration; opportunity to ask questions; no coercion or undue influence |
| Documentation | Signed and dated informed consent form; copy provided to participant |
| Updates | New information that may affect willingness to participate must be communicated; re-consent if warranted |
| Special populations | Additional protections for vulnerable subjects (children, cognitively impaired, economically disadvantaged) |
| Witness | Required when participant cannot read; witness must be present during consent discussion and must sign the form |
“Critical Requirement: ICH E6(R2) Section 4.8.1 states that "neither the investigator, nor the trial staff, should coerce or unduly influence a subject to participate or to continue to participate in a trial." Informed consent is a process, not a form signature. The consent discussion must be documented.
Investigational Product Management
| Responsibility | ICH E6(R2) Section | Details |
|---|---|---|
| Accountability | 4.6 | Investigator is responsible for IP accountability at the site |
| Storage | 4.6.2 | Store per sponsor instructions and applicable regulatory requirements |
| Dispensing | 4.6.3 | Only to enrolled subjects per protocol; document dispensing |
| Compliance monitoring | 4.6.4 | Monitor subject compliance with IP use |
| Return/destruction | 4.6.5 | Account for unused IP; return to sponsor or document destruction |
| Blinding | 4.6.3 | Maintain blinding per protocol; document any unblinding |
Safety Reporting
| Event Type | Investigator Obligation | Timeline |
|---|---|---|
| Adverse Event (AE) | Record in source documents and CRF | Per protocol; typically within 24-72 hours of awareness |
| Serious Adverse Event (SAE) | Report to sponsor immediately | Immediately after becoming aware; typically within 24 hours |
| SAEs requiring expedited reporting | Report per protocol and regulatory requirements | Per sponsor-specified timelines (often same day notification) |
| Follow-up of AEs/SAEs | Continue follow-up until resolution, stabilization, or death | Until event resolved or adequately characterized |
Record Keeping
ICH E6(R2) Section 4.9 requires investigators to maintain:
| Record Type | Retention Requirement |
|---|---|
| Essential documents | Per ICH E6(R2) Section 8 list; retained per applicable regulatory requirements |
| Source documents | Original documents where data is first recorded; must be retained |
| Case Report Forms (CRFs) | Completed CRFs per sponsor and regulatory requirements |
| Retention period | Per applicable regulatory requirements (FDA: 2 years after NDA approval or 2 years after investigation discontinued; EU: 25 years per EU CTR 536/2014 Article 58) |
Sponsor Responsibilities
ICH E6(R2) Sections 5.1 through 5.23 define sponsor obligations. The sponsor is responsible for implementing and maintaining quality assurance and quality control systems to ensure the trial is conducted and data generated per protocol, GCP, and applicable regulatory requirements.
Quality Management
E6(R2) Section 5.0 (added by the R2 Addendum) introduced the risk-based quality management framework:
| QM Element | Requirement |
|---|---|
| Quality management system | Implement a system proportionate to the risks inherent in the trial and the importance of the data collected |
| Critical process and data identification | Identify processes and data that are critical to ensuring participant safety and data reliability |
| Risk identification | Identify risks to critical processes and data |
| Risk evaluation | Evaluate identified risks in terms of probability, detectability, and impact |
| Risk control | Define risk reduction activities; accept residual risk; communicate risks |
| Risk review | Periodically review risk control measures; adapt as needed |
| Risk reporting | Document quality management activities and communicate results |
Monitoring
ICH E6(R2) Section 5.18 defines monitoring requirements, with the R2 Addendum significantly modernizing the approach:
| Monitoring Aspect | Traditional Approach | Risk-Based Approach (E6(R2)) |
|---|---|---|
| On-site monitoring | 100% source data verification (SDV) | Targeted SDV based on risk assessment |
| Centralized monitoring | Limited | Recommended as a complement or alternative to on-site monitoring |
| Frequency | Fixed schedule | Risk-based; higher frequency for higher-risk sites/data |
| Focus | All data points equally | Priority on critical data and processes |
| Statistical methods | Rare | Encouraged for data trend detection |
Centralized monitoring (Section 5.18.3) includes:
- Statistical analysis of data trends across sites
- Identification of data anomalies (outliers, missing data, unusual patterns)
- Assessment of protocol compliance across sites
- Evaluation of data consistency and plausibility
Investigational Product Management (Sponsor)
| Responsibility | ICH E6(R2) Section | Details |
|---|---|---|
| Manufacturing | 5.13.1 | IP manufactured per applicable GMP (ICH Q7 for APIs, regional GMP for products) |
| Labeling | 5.13.2 | Label per applicable regulatory requirements; blinding maintained as needed |
| Supply and accountability | 5.13.3 | Adequate supply; documentation of shipment, receipt, disposition, return, destruction |
| Storage | 5.13.4 | Proper storage conditions maintained; temperature monitoring |
| Randomization and unblinding | 5.13.5 | Procedures for randomization codes and emergency unblinding |
Data Handling and Record Keeping
ICH E6(R2) Section 5.5 addresses electronic data systems:
| Requirement | Details |
|---|---|
| Validation | Electronic systems used for clinical trial data must be validated for their intended use |
| Audit trail | Complete audit trail of data changes; original data retained; reason for change documented |
| Access control | Access limited to authorized individuals; user-specific credentials |
| Data backup | Regular backup; disaster recovery procedures |
| Blinding | Electronic systems must maintain blinding when applicable |
| SOPs | Written SOPs for electronic system use, data entry, data correction, backup |
IRB/IEC Requirements
ICH E6(R2) Section 3 defines the responsibilities, composition, functions, and operations of Institutional Review Boards (IRBs) / Independent Ethics Committees (IECs).
Composition
| Requirement | ICH E6(R2) Section 3.2 |
|---|---|
| Minimum membership | At least 5 members |
| Diversity | Both sexes; at least one member not affiliated with the institution; at least one non-scientific member |
| Expertise | Qualified to review the proposed trial (medical, scientific, ethical competence) |
| Special expertise | When reviewing trials involving vulnerable populations or specialized areas, members or consultants with relevant expertise should participate |
| Independence | Members should not participate in decisions on trials in which they have a conflict of interest |
IRB/IEC Review Requirements
| Document/Action | IRB/IEC Must Review | Reference |
|---|---|---|
| Protocol and amendments | Yes | 3.1.2 |
| Informed consent form and updates | Yes | 3.1.2 |
| Subject recruitment procedures and materials | Yes | 3.1.2 |
| Investigator's Brochure | Yes | 3.1.2 |
| Available safety information | Yes | 3.1.2 |
| Compensation to subjects | Yes | 3.1.2 |
| Investigator qualifications | Yes | 3.1.2 |
| Insurance provisions (where applicable) | Yes | Regional requirements |
Continuing Review
| Activity | Frequency | Purpose |
|---|---|---|
| Continuing review | At least annually; more frequently if warranted | Ongoing assessment of risk-benefit balance |
| Safety report review | As received | Evaluate impact on participant safety |
| Protocol deviation review | As reported | Assess impact on participant safety and data integrity |
| Amendment review | Before implementation | Ensure continued ethical acceptability |
Essential Documents
ICH E6(R2) Section 8 defines the essential documents that must be maintained during clinical trial conduct. These documents serve three purposes: they allow GCP compliance to be evaluated, they demonstrate data quality, and they protect participant rights.
Documents Before Trial Commencement
| Document | Filed By |
|---|---|
| Investigator's Brochure | Sponsor and investigator |
| Signed protocol and amendments | Sponsor and investigator |
| IRB/IEC approval | Investigator (to sponsor) |
| Informed consent form (approved) | Sponsor and investigator |
| Financial disclosure forms | Investigator (to sponsor) |
| Insurance documentation (if applicable) | Sponsor |
| Regulatory authority authorization | Sponsor |
| CVs of investigator and sub-investigators | Investigator (to sponsor) |
| Laboratory certifications and normal ranges | Investigator |
| Sample of label for IP | Sponsor |
| Shipment records for IP | Sponsor and investigator |
| Certificate of analysis for IP | Sponsor |
| Decoding procedures for blinded trials | Sponsor |
| Randomization list | Sponsor (sealed at site if applicable) |
| Trial master file index | Sponsor and investigator |
Documents During Trial Conduct
| Document | Filed By |
|---|---|
| IRB/IEC continuing review approvals | Investigator (to sponsor) |
| Updated Investigator's Brochure | Sponsor |
| Monitoring visit reports | Sponsor |
| Relevant communications (sponsor-investigator) | Both |
| SAE reports and correspondence | Both |
| Source documents | Investigator |
| Completed CRFs | Both |
| IP accountability records | Investigator |
| Subject screening and enrollment logs | Investigator |
| Signature/delegation log | Investigator |
Documents After Trial Completion
| Document | Filed By |
|---|---|
| IP accountability at site | Investigator |
| Documentation of IP destruction | Sponsor or investigator |
| Final monitoring report | Sponsor |
| Clinical study report | Sponsor |
| IRB/IEC notification of trial completion | Investigator |
| Regulatory authority notification of trial completion | Sponsor |
| Audit certificate (if audited) | Sponsor |
| Final subject disposition | Investigator |
“Trial Master File (TMF): All essential documents should be organized in a Trial Master File. The DIA TMF Reference Model provides a standardized structure for TMF organization. Electronic TMFs (eTMFs) must meet the same completeness and accessibility requirements as paper TMFs, with the additional requirements for electronic records (audit trail, access control, backup).
Electronic Records and Data Integrity
ICH E6(R2) Section 5.5 and the R2 Addendum address electronic records in clinical trials. These requirements intersect with FDA 21 CFR Part 11 (Electronic Records; Electronic Signatures) and EMA Annex 11 (Computerised Systems).
Electronic Data Capture (EDC) Requirements
| Requirement | Source | Expectation |
|---|---|---|
| System validation | E6(R2) 5.5.3 | EDC system validated for intended use before trial use |
| Audit trail | E6(R2) 5.5.3 | Complete, timestamped audit trail of all data changes |
| Data lock procedures | E6(R2) 5.5.3 | Database lock after data cleaning and query resolution |
| Access controls | E6(R2) 5.5.3 | Role-based access; individual user credentials |
| Electronic signatures | 21 CFR Part 11 / Annex 11 | Compliant with regulatory requirements for e-signatures |
| Data backup | E6(R2) 5.5.3 | Regular backup with documented recovery procedures |
| Blinding maintenance | E6(R2) 5.5.3 | System design must prevent unauthorized unblinding |
Source Data and Source Documents
ICH E6(R2) Section 1.52 defines source data as "all information in original records and certified copies of original records of clinical findings, observations, or other activities in a clinical trial necessary for the reconstruction and evaluation of the trial."
| Source Data Principle | Requirement |
|---|---|
| Original records | Data first recorded in source documents (medical records, lab printouts, diaries) |
| Certified copies | Must be verified as exact copies; used when originals are not available for monitoring |
| Attributable | Clear who made the entry and when |
| Legible | Readable and understandable |
| Contemporaneous | Recorded at the time the observation is made |
| Original | First recording of the data |
| Accurate | Free from error; corrections traceable |
These principles are commonly summarized as the ALCOA+ framework (Attributable, Legible, Contemporaneous, Original, Accurate, plus Complete, Consistent, Enduring, Available).
Risk-Based Quality Management (E6(R2) Addendum)
The most significant addition in E6(R2) is the integrated Addendum on risk-based quality management, added to Section 5.0.
Quality by Design for Clinical Trials
The E6(R2) Addendum applies QbD-like thinking to clinical trial design:
| Step | Activity | Deliverable |
|---|---|---|
| 1 | Identify critical data and processes | List of factors critical to participant safety and data reliability |
| 2 | Perform risk assessment | Risk identification, evaluation, and prioritization |
| 3 | Define risk control measures | Monitoring plan, training, system controls, data checks |
| 4 | Accept residual risks | Documented acceptance of risks that cannot be further mitigated |
| 5 | Communicate risks | Share risk information with relevant stakeholders |
| 6 | Review and adapt | Ongoing risk review throughout the trial lifecycle |
Impact on Monitoring Strategy
The risk-based approach transforms monitoring from a compliance exercise (visit every site, verify every data point) to a quality management activity:
| Traditional 100% SDV | Risk-Based Monitoring |
|---|---|
| Monitor visits every site at fixed intervals | Visit frequency based on site risk profile |
| Verifies all CRF data against source | Targeted SDV of critical data points |
| Limited centralized oversight | Central statistical monitoring as primary detection method |
| Resource-intensive | More efficient resource allocation |
| All sites treated equally | Resources focused on higher-risk sites |
“Regulatory Expectation: Both FDA and EMA have endorsed risk-based monitoring. FDA's 2013 guidance "Oversight of Clinical Investigations — A Risk-Based Approach to Monitoring" explicitly supports centralized monitoring and targeted SDV. The E6(R2) Addendum codifies this at the ICH level.
ICH E6(R3): The Upcoming Revision
ICH E6(R3) is under development, with a Step 2b draft released in May 2023. While not yet adopted, the key themes indicate the direction of GCP evolution:
| Theme | E6(R2) Approach | E6(R3) Direction |
|---|---|---|
| Trial designs | Primarily traditional randomized controlled trials | Accommodates decentralized trials, adaptive designs, master protocols |
| Data sources | Primarily site-generated CRF data | Includes real-world data, wearables, electronic health records |
| Informed consent | Paper-based process | Electronic consent (eConsent) explicitly addressed |
| Monitoring | Site-centric with centralized monitoring encouraged | Central monitoring as default with on-site monitoring as supplement |
| Technology | Electronic systems addressed as an addendum | Technology-agnostic, with principles for any current or future technology |
| Proportionality | Risk-based quality management introduced | Proportionate approach embedded throughout (lower-risk trials may have reduced requirements) |
Key Takeaways
References
Yes. ICH E6 applies to all clinical trials that may be submitted to regulatory authorities. When the investigator is also the sponsor (investigator-initiated studies), that individual assumes both sets of responsibilities. Regulatory agencies (FDA, EMA) apply GCP requirements to all clinical data submitted in support of marketing applications, regardless of who sponsored the trial.