Adverse event reporting in clinical trials: what ICH GCP requires and how to get it right
In clinical research, the safety of participants is not simply a moral obligation; it is a regulatory imperative, and the mechanism through which that imperative is enforced is adverse event reporting. When a participant in a clinical trial experiences a medical event, the way that event is classified, assessed, and reported can determine whether a regulatory authority takes action, whether a trial is suspended, and ultimately whether a medicine reaches patients safely or not.
Adverse event reporting in clinical trials is one of the most scrutinised areas of ICH GCP compliance. It is also one of the most commonly misunderstood. The distinctions between an adverse event and a serious adverse event, between a serious adverse event and a SUSAR, and between a 24-hour report and a 15-day report are not academic; they are the operational knowledge that every investigator, coordinator, sponsor, and CRA needs to get right, every time.
This guide gives you the complete picture: definitions, timelines, responsibilities, classification criteria, and the specific updates that ICH E6 R3 introduced to safety reporting in 2025.
Adverse event reporting in clinical trials is the systematic process of identifying, classifying, assessing, and communicating medical events experienced by trial participants to investigators, sponsors, ethics committees, and regulatory authorities. Under ICH GCP, every adverse event must be recorded, every serious adverse event must be reported to the sponsor within defined timelines, and certain unexpected serious reactions must be expedited to regulatory authorities and ethics committees within 7 or 15 days.
What is an adverse event in clinical trials?
The "Adverse Event" definition under ICH GCP
An adverse event (AE) in a clinical trial is any untoward medical occurrence in a participant who has been administered a study treatment, regardless of whether there is a causal relationship between the treatment and the event. This definition, drawn from the ICH GCP E6 guidance, is deliberately broad. The word “untoward” means unfavourable or unwanted. The phrase “regardless of causal relationship” means that an investigator does not need to believe the event was caused by the study treatment to record and report it as an adverse event.
This breadth is intentional. Clinical trials are conducted precisely because the full safety profile of an investigational product is not yet known. If only clearly drug-related events were recorded, the cumulative safety signal that emerges from a clinical programme, the pattern of events across hundreds or thousands of participants, would be contaminated by investigator judgment and potentially miss important safety information. Every adverse event reported in a clinical trial, regardless of perceived causality, contributes to the safety database that regulators use to assess whether a treatment can be approved for use in the general population.
Under ICH GCP good clinical practice guidance, all adverse events must be recorded in source documents and reported to the sponsor according to the timelines specified in the protocol. The investigator is responsible for ensuring that every adverse event experienced by a participant under their care is identified, assessed, and documented. This responsibility cannot be delegated to a coordinator without the investigator retaining overall accountability for the completeness and accuracy of adverse event reporting at the site.
What are examples of adverse events in clinical trials?
Examples of commonly reportable adverse events are the following:
- nausea and vomiting after chemotherapy (non-serious),
- anaphylaxis following first dosing (potentially life-threatening SAE),
- a road traffic accident during a trial (SAE but likely unrelated),
- an unexpected liver enzyme elevation (potentially SUSAR-qualifying)
What adverse event reporting in clinical trials requires at site level
At site level, adverse event reporting in clinical trials begins with the recognition of a medical event by any member of the site team, the investigator, the study nurse, the coordinator, or the participant themselves at a scheduled study visit or through a spontaneous report between visits. Every event identified must be entered into the source record at the time it is identified or as soon as practicable thereafter, in accordance with the ALCOA++ principles of contemporaneous and accurate documentation.
The investigator must then assess the event on several dimensions: its severity, its seriousness, its relationship to the study treatment, and whether it was expected based on the investigator brochure or prescribing information. Each of these assessments determines what happens next and on what timeline.
"Adverse Event" vs "Serious Adverse Event": understanding the critical distinction
What makes an "adverse event" serious?
The classification of an adverse event as serious, making it a serious adverse event (SAE), is one of the most consequential determinations in adverse event reporting in clinical trials. An SAE is not simply a severe adverse event. Severity and seriousness are different concepts that are frequently confused in clinical practice.
Severity describes the intensity of the event, mild, moderate, or severe, on a clinical scale. A severe headache is intense but may not be serious. Seriousness, by contrast, is a regulatory classification based on predefined criteria. An event is classified as a serious adverse event if it meets any one of the following criteria under ICH GCP and ICH E2A:
- It results in death. Any death occurring in a clinical trial participant must be treated as an SAE and reported according to the relevant regulatory and protocol timelines, regardless of whether the investigator believes the death is related to the study treatment.
- It is life-threatening. An event is life-threatening if the participant is at immediate risk of death at the time of the event. This does not include events that might theoretically be fatal if they were more severe; it refers to events that, as they occurred, placed the participant’s life in immediate danger.
- It requires inpatient hospitalization or prolongation of existing hospitalization. Any unplanned admission to hospital, or any extension of an existing hospital stay beyond what would have occurred without the event, meets the seriousness criterion. Elective admissions planned before the participant enrolled, and admissions for pre-existing conditions not worsened by the study treatment, do not automatically qualify.
- It results in persistent or significant disability or incapacity. A substantial disruption to a person’s ability to conduct normal life functions that is persistent, not transient, meets this criterion.
- It is a congenital anomaly or birth defect. Any congenital anomaly identified in the offspring of a participant or their partner meets the seriousness criterion regardless of the mechanism or perceived relationship to the study treatment.
- It is a medically significant event. This is the criterion that requires the most investigator judgment and is examined in more detail below.
Adverse event grading: what do grades 1 to 5 mean in clinical trials?
The Common Terminology Criteria for Adverse Events (CTCAE), developed by the US National Cancer Institute, is the standard grading system used in clinical trials to classify the severity of adverse events. Wikipedia presents this clearly:
Grade 1: Mild AE
Grade 2: Moderate AE
Grade 3: Severe AE
Grade 4: Life-threatening or disabling AE
Grade 5: Death related to AE
What is an adverse drug reaction (ADR) and how does it differ from an adverse event?
An “Adverse Drug Reaction” (ADR) is not the same as an “Adverse Event” (AE). An AE requires no causal relationship; an ADR implies at least a suspected causal relationship between the drug and the event.
What is medically significant in pharmacovigilance?
The “medically significant” criterion for serious adverse event classification is the catch-all category that requires investigators and pharmacovigilance teams to exercise clinical judgement. Under ICH guidance, a medically significant event is one that, although it may not immediately threaten life or require hospitalisation, may jeopardise the participant or may require intervention to prevent one of the other serious outcomes listed above.
In practice, medically significant events in pharmacovigilance include: important medical reactions that do not reach the threshold of life-threatening or hospitalisation but are considered significant by experienced clinicians; conditions such as drug dependence or drug abuse; significant laboratory abnormalities that require medical intervention; events that require treatment in an emergency department without leading to inpatient admission; and events that, based on medical and scientific judgement, would be expected to be considered serious by regulatory reviewers.
The medically significant criterion exists because the defined categories of seriousness cannot capture every situation in which a participant’s safety requires expedited regulatory attention. In adverse event reporting in clinical trials, the “when in doubt, report as serious” principle applies to this category, the cost of under-reporting a medically significant event is always higher than the cost of over-reporting one.
Adverse event vs SAE vs SUSAR: the complete classification framework
What is a SUSAR?
A SUSAR, a Suspected Unexpected Serious Adverse Reaction, is a specific category of serious adverse event that carries the most urgent reporting timeline in clinical research. Understanding what makes a serious adverse event a SUSAR requires unpacking three components: suspected, unexpected, and serious.
“Suspected” means the investigator or sponsor considers it at least possible that there is a causal relationship between the study treatment and the event. A serious adverse event that is clearly unrelated to the study treatment, for example, a road traffic accident, is not a suspected adverse reaction and does not qualify as a SUSAR, though it must still be reported as an SAE.
“Unexpected” means the event is not consistent with the reference safety information for the investigational product, typically the investigator brochure for unapproved treatments, or the summary of product characteristics for approved medicines used in the study. An event is unexpected if its nature, severity, or frequency is not described in the current reference safety information, or if it occurs in a patient population not described therein. If an event is listed in the investigator’s brochure, even as a known risk, it is an expected adverse reaction and does not qualify as a SUSAR even if it is serious and suspected to be related.
“Serious” means the event meets one or more of the seriousness criteria described above.
All three components must be present simultaneously for an event to be classified as a SUSAR. Missing any one of the three changes the classification and the reporting pathway.
The adverse event classification hierarchy
Understanding the relationship between these classifications is essential for correct adverse event reporting in clinical trials:
All events experienced by participants are adverse events. Adverse events that meet the seriousness criteria become serious adverse events. Serious adverse events that are also suspected to be related to the study treatment become suspected serious adverse reactions (SARs). Suspected serious adverse reactions that are also unexpected become SUSARs. SUSARs trigger the most urgent regulatory reporting obligations.
This hierarchy determines the reporting pathway, the reporting timeline, and the recipient of the report at every level of the clinical trial oversight structure.
SAE reporting timelines under ICH GCP: the 24-hour, 7-day, and 15-day rules
Why timelines matter in adverse event reporting
Timelines in adverse event reporting in clinical trials are not administrative formalities, they reflect the urgency with which safety information must reach those who need it to protect participants. A serious adverse event that is not reported within the required timeline represents a GCP violation regardless of whether harm resulted from the delay. Regulatory authorities treat reporting timeline failures as indicators of systemic quality problems at the site or sponsor level.
The timeline obligations in adverse event reporting in clinical trials operate at two levels: the site-to-sponsor timeline and the sponsor-to-regulatory authority timeline.
The 24-hour rule: site to sponsor SAE reporting
Under ICH GCP good clinical practice guidance, the investigator must report all serious adverse events to the sponsor immediately after they first become aware of the event. In practice, most protocols specify a 24-hour timeline for initial SAE reporting from the site to the sponsor, even when the event is not yet fully characterised. This initial report is called a “flash report” or “initial report” and may contain incomplete information, what matters is that the sponsor receives notification within 24 hours of the investigator’s awareness, so that sponsor-level assessment and regulatory reporting obligations can be initiated in parallel with site-level investigation of the event.
Fatal and life-threatening SUSARs have even more urgent site-level reporting requirements in many protocols, some specify immediate notification by telephone within hours of the event becoming known, followed by written documentation within 24 hours.
The 7-day rule: fatal and life-threatening SUSARs to regulatory authorities
Under ICH E2A, the ICH guideline on clinical safety data management, sponsors must report fatal and life-threatening SUSARs to regulatory authorities and relevant ethics committees within 7 calendar days of the sponsor’s first awareness of the event. This 7-day report is an initial report and may be followed by a more complete follow-up report within 8 additional days (total 15 days from the date of awareness).
The 7-day rule applies regardless of where in the world the event occurred. A fatal SUSAR identified at a site in South Korea must be reported to the FDA, EMA, and all other relevant regulatory authorities within 7 days if the investigational product is being developed for those markets.
The 15-day rule: all other SUSARs to regulatory authorities
Non-fatal, non-life-threatening SUSARs must be reported to regulatory authorities and ethics committees within 15 calendar days of the sponsor’s first awareness. This 15-day rule also applies to follow-up reports for SUSARs initially submitted under the 7-day rule.
For regulatory authorities in specific jurisdictions, additional timelines and report formats may apply. The FDA’s IND safety reporting regulations under 21 CFR 312.32 specify 7-day and 15-day timelines consistent with ICH E2A. The EMA’s requirements under EU Clinical Trials Regulation 536/2014 similarly specify these timelines but add specific provisions for the EudraCT database submission. Sponsors conducting global trials must satisfy the requirements of every jurisdiction in which the trial is registered.
Protocol deviation timelines for AE reporting
Beyond the SAE and SUSAR timelines, protocols typically specify timelines for reporting all adverse events, including non-serious ones, in the case report form (CRF). Most protocols require that all adverse events be recorded in the CRF within a defined window, often 7 days of the study visit at which the event was identified or reported. Failure to record adverse events in the CRF within the protocol-specified window is a protocol deviation, not merely a documentation oversight, and may be flagged at monitoring visits and inspections.
Who is responsible for adverse event reporting in clinical trials?
Investigator responsibilities for AE reporting
The investigator’s responsibilities in adverse event reporting in clinical trials begin the moment a participant enters the study and continue until the participant’s last study contact. Under ICH GCP good clinical practice guidances, the investigator must ensure that all adverse events are identified, assessed, recorded in source documents, and reported to the sponsor within the timelines specified in the protocol.
Specifically, the investigator must: conduct the clinical assessment of each adverse event to determine its severity, seriousness, and relationship to the study treatment; sign and date the SAE report submitted to the sponsor, confirming the accuracy of the clinical information; follow up any ongoing adverse event at each subsequent study visit and update the report with follow-up information until the event resolves or reaches a stable end state; and provide any additional information requested by the sponsor for regulatory reporting purposes within the timeframes required.
The investigator may delegate the administrative aspects of adverse event reporting, completing the SAE form, and entering data into the sponsor’s safety reporting portal, to a trained coordinator or sub-investigator documented on the delegation of authority log. However, the clinical assessment of causality and seriousness must be made by a qualified physician. The investigator cannot delegate the medical judgment element of adverse event reporting in clinical trials.
For a full guide to investigator obligations under GCP, see our guide to principal investigator responsibilities under ICH GCP.
Sponsor responsibilities for AE reporting
The sponsor carries the most extensive obligations in the adverse event reporting system. Under ICH GCP, the sponsor must: receive and review all SAE reports from investigators across all sites; assess each SAE for expectedness (comparison against the reference safety information) and causality; determine whether the event meets SUSAR criteria; prepare and submit expedited safety reports to all relevant regulatory authorities and ethics committees within the required timelines; and distribute line listings and Development Safety Update Reports (DSURs) to all investigators and ethics committees according to the applicable schedule.
In many programs, the sponsor delegates pharmacovigilance functions, including SAE receipt, processing, and expedited reporting, to a contract research organization. Under ICH GCP E6 R3, this delegation must be specified in writing in the sponsor-CRO agreement, and the sponsor retains ultimate accountability for the quality and timeliness of all safety reporting, regardless of delegation. For a full guide to the sponsor-CRO relationship, see our guide to what is a contract research organization.
Ethics committee (IRB/IEC) responsibilities
Ethics committees must receive SAE reports and, specifically, SUSAR line listings and safety reports submitted by the sponsor throughout the trial. Ethics committees use this information to assess the ongoing risk-benefit balance of the study. If the accumulating safety information indicates that risks to participants have materially changed, the ethics committee may require protocol amendments, informed consent updates, or suspension of enrollment. For a full guide to the role of ethics committees in clinical research, see our guide to what is good clinical practice.
Regulatory authority submission
Regulatory authorities, including the FDA (United States), EMA (Europe), MHRA (United Kingdom), and their counterparts in other jurisdictions, are the ultimate recipients of expedited safety reporting. They use SUSAR reports, aggregate safety analyses, and Development Safety Update Reports to monitor the safety profile of investigational products throughout the development programme and to identify signals that may require regulatory intervention, including imposition of a clinical hold, requirement for protocol amendments, or withdrawal of the investigational new drug application.
Once a product is approved, the post-marketing surveillance system continues to operate, reporting adverse events through various systems: the FDA’s FAERS (MedWatch) in the US, the EMA’s EudraVigilance in Europe, and the MHRA’s Yellow Card Scheme in the UK.
ICH E6 R3 updates to safety reporting
What changed in safety reporting under R3?
ICH GCP E6 R3, the current version of the good clinical practice guidelines adopted in January 2025, does not fundamentally alter the established adverse event reporting timelines or classification criteria; these are governed by ICH E2A and continue to apply as before. What R3 does introduce are important contextual changes that affect how safety reporting is managed in practice.
Quality by design applied to safety reporting
ICH GCP R3’s principle of quality by design has specific implications for adverse event reporting in clinical trials. The expectation is that sponsors design safety reporting systems proactively, identifying Critical to Quality (CtQ) factors for safety data collection before the trial begins, rather than addressing safety reporting failures reactively. This means that the SAE form design, the investigator site file structure for safety documentation, the sponsor’s pharmacovigilance SOP, and the site training programme should all be reviewed before first participant enrolment for their ability to support timely, complete, and accurate adverse event reporting.
Sponsors who apply quality by design to their safety reporting systems are better positioned to identify reporting delays, data quality issues, and protocol deviation patterns before they become inspection findings. This proactive approach is a direct expression of R3’s shift from reactive compliance to active quality ownership.
Proportionality and safety reporting
ICH GCP R3’s proportionality principle requires that safety reporting processes be proportionate to the trial’s risk. A first-in-human oncology study with a novel investigational product carries fundamentally different safety monitoring requirements than a low-intervention observational study of an approved medication. Under R3, sponsors are expected to design safety reporting systems that match the intensity of oversight to the actual risk, rather than applying uniform, maximum-intensity reporting processes to all studies regardless of their risk profile.
In practice, this means that the frequency of safety data review, the intensity of monitoring at sites, and the complexity of SAE reporting workflows should be calibrated to the specific risk characteristics of each study. For professionals completing ICH GCP good clinical practice training or ICH GCP good clinical practice certification, understanding this proportionality principle is essential for designing and operating safety reporting systems that are both compliant and efficient.
Decentralised trials and remote safety data collection
ICH E6 R3 is the first version of the good clinical practice guidance to explicitly address decentralised clinical trials, studies in which some or all trial activities take place outside the traditional investigator site, including home visits, remote assessments, and wearable device data collection. For adverse event reporting in clinical trials conducted in a decentralised model, R3 creates new challenges that do not exist in conventional site-based trials.
When participants interact with the trial remotely, adverse events may be self-reported through digital platforms rather than identified at a site visit. The investigator’s responsibility to identify, assess, and report all adverse events does not change in a decentralised model, but the systems that support AE identification must be adapted. R3 requires that sponsors ensure that remote adverse event identification and reporting processes are validated, auditable, and capable of generating the contemporaneous documentation required by ALCOA++ principles.
For a complete guide to ALCOA++ and documentation standards in GCP, see our guide to good documentation practice.
Common adverse event reporting failures and how to avoid them
Reporting delays
Adverse event underreporting is one of the most documented problems in clinical research. Studies indicate that up to half of all adverse events occurring in clinical trials are never formally recorded, with reporting rates varying significantly by therapeutic area, site experience, and investigator training level. The most common adverse event reporting failure in clinical research is a simple delay; a “Serious Adverse Event” is identified at the site but is not communicated to the sponsor within the 24-hour protocol requirement because the site team is unaware of the event, does not recognize it as serious, or lacks the documentation systems to act quickly. The most effective preventive measure is site-level training; every member of the site team must understand what constitutes a serious adverse event, how to record it immediately in source documents, and how to initiate contact with the sponsor without waiting for a scheduled monitoring visit.
Near-miss events
Near-miss events are safety failures that occurred but did not cause harm. They should also be documented and investigated as part of the trial’s quality management system, as per the ICH E6 R3 quality by design framework.
These events are events with the potential to cause significant harm but did not result in harm, typically due to chance. In the clinical trial context, near-misses are relevant because they may indicate systemic safety risks that should be reported through quality management systems, even if no participant was harmed.
Incorrect seriousness classification
Under-classifying a serious adverse event as non-serious, because the investigator does not recognise that it meets one of the seriousness criteria, is a frequent inspection finding with potentially significant consequences. The most commonly missed seriousness criteria are medically significant events (often under-reported because the criterion is subjective) and prolongation of hospitalisation (sometimes overlooked when participants are already inpatients for other reasons). Training on the precise definitions and their application to realistic clinical scenarios is the most effective preventive measure.
Incorrect causality assessment
Assigning “not related” causality to an event that a regulatory authority later classifies as related is a finding that can undermine the integrity of a clinical programme’s safety database. Investigators sometimes assign “not related” causality based on their prior beliefs about the drug rather than on the clinical evidence available at the time of the event. Under GCP, causality assessment should be made on the basis of the available evidence, the temporal relationship, known mechanisms, dechallenge and rechallenge data where available, not on assumptions about the treatment’s mechanism of action.
Failure to follow up
A Serious Adverse Event that is reported initially but not followed up until resolution, leaving the report open indefinitely with no updated information, is a documentation deficiency that creates an incomplete safety record. Protocols typically require that open SAEs be followed until resolution or until a stable end state has been documented. Site teams must have systems to track all open SAE reports and ensure that follow-up information is submitted to the sponsor as new information becomes available.
Key takeaways
Adverse event reporting in clinical trials is the cornerstone of participant safety in clinical research and one of the most scrutinised areas of GCP compliance. Every clinical research professional involved in trial conduct, investigators, coordinators, CRAs, pharmacovigilance specialists, and sponsor oversight teams, needs a precise, working understanding of the classification criteria, timelines, and responsibilities that govern this process.
An adverse event is any untoward medical occurrence in a trial participant, regardless of causal relationship to the study treatment. An SAE is an adverse event meeting at least one of six defined seriousness criteria. A SUSAR is an SAE that is also suspected to be related to the investigational product and unexpected based on the current reference safety information. All three categories trigger different reporting obligations.
The reporting timelines are not negotiable: 24 hours for SAE notification from site to sponsor, 7 calendar days for fatal and life-threatening SUSARs to regulatory authorities, and 15 calendar days for all other SUSARs to regulatory authorities. Protocol-specified CRF entry timelines apply separately to all adverse events.
The investigator is responsible for the clinical assessment of every adverse event at the site. The sponsor, or delegated CRO, is responsible for expedited regulatory reporting. Both parties bear accountability for the completeness and timeliness of the overall adverse event reporting system.
ICH E6 R3 has added quality by design, proportionality, and decentralised trial provisions to the safety reporting framework without changing the core timelines and classification criteria. For professionals completing ICH GCP good clinical practice training or pursuing ICH GCP good clinical practice certification, understanding both the established framework and the R3 updates is essential for 2026 compliance.
Conclusion
Adverse event reporting in clinical trials is where patient safety becomes paperwork, and where the quality of that paperwork determines whether the safety signal embedded in a trial’s data is ever seen by the people who need to act on it. Every delayed report, every missed seriousness criterion, every unsent follow-up is not merely a protocol deviation. It is a gap in the information system that exists specifically to protect the participants who trusted the research community enough to enrol.
The framework for adverse event reporting, from the initial site identification through to regulatory submission of SUSARs, is one of the most carefully constructed systems in clinical research. It has been built over decades of regulatory evolution, informed by the lessons of trials in which safety information was lost, delayed, or misclassified. Understanding this framework is not optional for anyone involved in the conduct of clinical trials, and knowing it well, well enough to apply it correctly under time pressure, with incomplete information, and in circumstances that do not perfectly fit the textbook definitions, is what distinguishes a genuinely GCP-competent professional.
Is your team ready to handle adverse event reporting correctly under ICH E6 R3?
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FAQ: adverse event reporting in clinical trials
What is an adverse event in a clinical trial?
An adverse event in a clinical trial is any untoward medical occurrence in a participant who has received a study treatment, regardless of whether there is a causal relationship between the treatment and the event. Under ICH GCP good clinical practice guidance, all adverse events must be recorded in source documents and reported to the sponsor according to the protocol-specified timelines. The definition is deliberately broad to ensure that all safety information is captured and contributes to the overall safety database for the investigational product.
What is the difference between an adverse event and a serious adverse event?
An adverse event is any untoward medical occurrence in a trial participant. A serious adverse event (SAE) is an adverse event that meets at least one of six defined seriousness criteria: death, life-threatening risk, inpatient hospitalisation or its prolongation, persistent or significant disability, congenital anomaly or birth defect, or medical significance. Severity and seriousness are distinct concepts; a severe event is not automatically serious, and a serious event is not necessarily clinically severe.
What is a SUSAR and when must it be reported?
A SUSAR is a Suspected Unexpected Serious Adverse Reaction, an SAE that is also suspected to be causally related to the investigational product and is not consistent with the current reference safety information (investigator brochure or summary of product characteristics). Fatal and life-threatening SUSARs must be reported to regulatory authorities within 7 calendar days. All other SUSARs must be reported within 15 calendar days. Adverse event reporting in clinical trials involving SUSARs is among the most time-sensitive compliance obligations in GCP.
What are the SAE reporting timelines under GCP?
Investigators must report SAEs to the sponsor within 24 hours of becoming aware of the event. Sponsors must report SUSARs to regulatory authorities within 7 calendar days (fatal and life-threatening) or 15 calendar days (all other SUSARs). These timelines are specified in ICH E2A and are reinforced by local regulatory requirements in each jurisdiction where the trial is registered. Protocol-specific CRF entry timelines apply separately to all adverse events.
Who is responsible for adverse event reporting in a clinical trial?
The investigator is responsible for identifying, assessing, and reporting all adverse events at the site, including the clinical assessment of seriousness and causality. The sponsor, or delegated CRO, is responsible for receiving SAE reports from sites, determining SUSAR status, and submitting expedited safety reports to regulatory authorities and ethics committees. Both the investigator and the sponsor carry non-transferable GCP accountability for the accuracy and timeliness of their respective reporting obligations.
What does medically significant mean in pharmacovigilance?
A medically significant event is an adverse event that, although it may not meet the other defined seriousness criteria (death, life-threatening, hospitalisation, disability, congenital anomaly), is considered by the investigator to be serious based on clinical judgement. Examples include important allergic reactions, drug dependence, significant laboratory abnormalities requiring intervention, and events requiring emergency department treatment without inpatient admission. The medically significant criterion exists to capture safety information that falls outside the defined categories but that experienced clinicians and regulators would consider serious.
What is the difference between expected and unexpected adverse events in GCP?
An expected adverse reaction is consistent with the current reference safety information, described in the investigator’s brochure or summary of product characteristics in terms of its nature, severity, and frequency. An unexpected adverse reaction is one not consistent with the reference safety information. The expected/unexpected distinction is one of the three components that determine whether a serious adverse event qualifies as a SUSAR and triggers expedited regulatory reporting.
What did ICH E6 R3 change about adverse event reporting?
ICH E6 R3 introduced quality by design requirements for safety reporting systems, requiring sponsors to design adverse event reporting processes proactively before the trial begins. It also introduced proportionality, the expectation that safety monitoring intensity be calibrated to the specific risk profile of each study. Additionally, R3 explicitly addressed safety data collection and adverse event reporting in decentralized clinical trials, where participants interact with the study remotely. The core reporting timelines and classification criteria, governed by ICH E2A, were not changed by R3.
Can an investigator delegate adverse event reporting to a coordinator?
Partially. The administrative aspects of adverse event reporting, completing the SAE form, and entering data into the sponsor’s reporting portal can be delegated to a trained coordinator documented on the delegation of authority log. However, the clinical assessment of an adverse event, determining its seriousness, causality, and classification, must be performed by a qualified physician. The investigator retains overall accountability for all adverse event reporting at the site, regardless of what has been delegated.
What happens if an SAE is not reported within the required timeline?
Late or missed SAE reporting is a GCP violation. It may be flagged as a finding at a monitoring visit or regulatory inspection, classified as a protocol deviation or serious GCP violation depending on severity, and may result in action by the sponsor, including site retraining, increased monitoring frequency, or in serious cases, site suspension. In the most severe cases, where unreported or delayed SAEs are found to have affected participant safety across multiple sites, regulatory authorities may place a clinical hold on the entire study.
What are grade 1, 2, 3, 4, and 5 adverse events?
The CTCAE grading system classifies adverse event severity on a five-point scale: Grade 1 (mild), Grade 2 (moderate), Grade 3 (severe), Grade 4 (life-threatening or disabling), and Grade 5 (death related to the adverse event). This grading system is distinct from the regulatory seriousness classification used in ICH GCP, a severe Grade 3 event may or may not be a serious adverse event depending on whether it meets the defined seriousness criteria.
What is the difference between an adverse event and an adverse drug reaction?
An adverse event (AE) is any untoward medical occurrence in a clinical trial participant, regardless of whether there is a suspected relationship to the study treatment. An adverse drug reaction (ADR) specifically implies that there is at least a suspected causal relationship between the drug and the event. All ADRs are adverse events, but not all adverse events are ADRs. This distinction determines whether an event triggers the “suspected” component required for SUSAR classification.
