Abstract 572P
Background
Immune-related adverse events (irAE) complicate the use of immune checkpoint inhibitors (ICI). There are limited real-world studies examining potential contributors to identify patients at risk. We aimed to estimate rates of irAE among patients in hospital admitted and emergency episodes across Victoria, Australia using linked administrative datasets.
Methods
We analysed episodes of care coded by International Statistical Classification of Diseases and Related Health Problems 10 th Revision Australian Modification (ICD-10-AM) to infer irAE-related admissions/visits. We used the PRedicting the population health economic IMpact of current and new CAncer Treatments dataset containing patients in Victorian Cancer Registry diagnosed with specific cancers between 2010-2021. Patients were linked to Commonwealth datasets (Pharmaceutical Benefits Scheme [PBS], Medicare Benefits Scheme, National Death Index). We developed definitions for irAE occurrence based on ICD-10-AM codes. We identified patients who received at least one ICI dose (ipilimumab, nivolumab, pembrolizumab, durvalumab, avelumab, atezolizumab, cemiplimab) in PBS. We applied the definitions to the Victorian Admitted Episodes Dataset (VAED) and Victorian Emergency Minimum Dataset (VEMD) to estimate irAE occurrence rates among ICI exposed patients.
Results
Among 213,476 patients, 7,061 received at least one ICI dose. Colitis/enterocolitis was the most identified irAE inferred in VAED and VEMD. Combined rate for all colitis/enterocolitis definitions was 21.35%. Rarer irAE types were inferred from VAED including neurological and cardiac. Inference rate of neuropathy was 1.06%. Inference rates for myocarditis and pericarditis were 0.82% and 0.68%, respectively.
Conclusions
Our findings are comparable to observational/cohort studies suggesting our method to infer irAE at a population-level may be appropriate but requires validation in different datasets. Identifying irAE occurrence is a crucial step towards evaluating factors associated with irAE risk, which is the next stage of research. Our project contributes to the growing knowledge on real-world irAE prevalence and underscores the potential use of administrative data to examine irAE risk factors.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
University of Melbourne.
Funding
Victorian Comprehensive Cancer Centre.
Disclosure
All authors have declared no conflicts of interest.