An Adverse Event of Special Interest (AESI) is a predefined category of adverse events that, on the basis of scientific and medical knowledge, requires particular attention and for which a predefined, expedited collection and assessment procedure is planned – regardless of whether the event is classified as serious.
AESIs are defined, depending on the known or suspected safety profile of the investigational medicinal product, in the study protocol and in the Risk Management Plan. Typical AESI categories are: immune-mediated reactions (e.g. with checkpoint inhibitors: pneumonitis, colitis), infusion reactions, hepatotoxic events, cardiovascular events (e.g. QT prolongation), or – as prominently seen in COVID-19 vaccine trials – myocarditis.
Unlike an SAE, an AESI does not require a severity classification but rather a predefined reporting and adjudication process. AESIs are generally assessed by a Clinical Endpoint Committee (CEC). For CROs, the correct capture, coding (MedDRA) and timely reporting of AESIs is a central pharmacovigilance task. Regulatory reference: ICH E6(R2), EMA Good Pharmacovigilance Practices (GVP).