The Prevalence and Patterns of Toxicity With Immune Checkpoint Inhibitors in Solid Tumors: A Real-World Experience From a Tertiary Care Center in Oman

Introduction Immune checkpoint inhibitors (ICIs) have revolutionized the management of multiple cancers over the last decade. They work by employing the immune system and exhibiting activity over T cells resulting in immune upregulation. Despite their widespread use, they produce side effects that can limit their use. The immune-related adverse events (irAEs) can be sometimes significant. The irAEs caused by ICIs may occur at any time during the treatment and can vary in grade (G). We sought to study the prevalence and toxicity patterns of ICIs in Oman. Methods One hundred forty-one adult patients (≥18 years) who received at least one dose of nivolumab, pembrolizumab, atezolizumab, or durvalumab between 2016 and 2022 were included. The data were analyzed retrospectively using univariable and multiple-variable logistic regressions. The Wilcoxon rank-sum test and Cochran-Armitage trend test were also used to summarize the continuous and ordinal data. Results Out of the 141 patients, 80 patients (56.7%) received pembrolizumab, and 48 (34%) received nivolumab. Common irAEs included endocrine abnormalities, pneumonitis, and colitis. Thirty patients (21.3%) experienced varying irAE grade toxicity. Out of the 30, 23 patients (82%) developed grade 2 and 3 irAEs. Discussion Predictive analysis showed that male sex and lower hemoglobin (Hb) and bilirubin levels were all significant predictors (p < 0.05) when associated with irAE occurrence. The prevalence of irAEs was similar compared to other reports, literature reviews, or meta-analyses. Female sex has been mentioned previously also to be a predictive factor for endocrine-related toxicities.