TEAE

Treatment-emergent adverse event (TEAE) is a term used in clinical trials and regulatory submissions to describe an adverse event that arises after exposure to a study treatment or that worsens after the start of treatment. TEAEs are identified during the post-baseline period, from the first dose until a predefined cut-off, such as end of treatment or a specified follow-up window. They may include new events not present at baseline, or pre-existing conditions that increase in severity or frequency after treatment initiation.

Data on TEAEs are collected, coded, and analyzed to characterize a treatment’s safety profile. TEAEs are typically coded using MedDRA terms and graded for severity according to criteria such as CTCAE, with timing relative to treatment and causality considered. While investigators assess possible relationships to the study drug, TEAE reporting is primarily a time-based measure rather than a definitive proof of causation. Incidence is usually presented by system organ class and preferred term, with information on severity and whether events are serious.

Distinctions and relationships to other safety terms are important. TEAEs and serious adverse events (SAEs) are not mutually exclusive; an event that emerges after treatment and meets seriousness criteria is both a TEAE and an SAE. Conversely, an event that occurred before treatment and does not worsen after treatment is not a TEAE. TEAEs are used to inform safety signals, tolerability, and dose-selection decisions, and are a key component of risk-benefit assessments in trials and regulatory submissions.