Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of several solid tumors, providing deep and durable responses for many patients. However, the anti-tumor mechanism of action of ICIs can also cause aberrantly active self-damaging immune responses, leading to immune-related adverse events (irAEs). The natural history, response to treatment, and patterns of irAEs vary widely, ranging from short-term inflammatory conditions to prolonged inflammation and damage to organs leading to permanent dysfunction. These diverse patterns of irAEs have been inconsistently described in the literature, making existing data difficult to interpret.
A generally accepted and shared vocabulary for irAEs is essential to standardize the application of clinical practice guidelines and offer the best treatment to patients. Recognizing this need, SITC convened an international consensus panel comprised of leading experts from academic medicine, industry, and regulatory agencies to develop definitions and uniform terminology for irAE natural history (ie, re-emergent, chronic-active, chronic-inactive, delayed/late-onset), response to treatment (ie, steroid-unresponsive, steroid-dependent), and patterns (ie, multisystem irAEs).
The result of this effort is our newest manuscript, “Society for Immunotherapy of Cancer (SITC) consensus definitions for immune checkpoint inhibitor-associated immune-related adverse events (irAEs) terminology,” now available in the Journal for ImmunoTherapy of Cancer, the society’s open-access, peer-reviewed online journal.
SITC developed these definitions to support the adoption of a standardized vocabulary for irAEs. The application of these definitions to future prospective trials may also assist in the identification of optimal management strategies as well as biomarker discovery and will further facilitate harmonization in guidelines, review articles, and subsequent consensus statements related to irAEs.