Rheumatic immune-related adverse events with immune checkpoint inhibitors more severe than previously reported

A recent study published in ACR Open Rheumatology reveals that rheumatic immune-related adverse events (rh-irAEs) experienced by patients receiving immune checkpoint inhibitors (ICIs) are more severe than previously understood. The research, conducted by Didzis Gailis and colleagues from Ludwig-Maximilians-Universität University Hospital in Munich, analyzed a multicenter observational registry of adults undergoing ICI therapy.

Of the 60 patients included in the study, 90% experienced moderate or severe rh-irAEs. The most common phenotype was rheumatoid arthritis-like polyarthritis, followed by polymyalgia rheumatica-like and peripheral spondyloarthritis-like syndrome. Younger patients were more likely to exhibit axial spondyloarthritis-like syndrome. Ninety percent of patients required systemic glucocorticoids (GCs), with 23.3% needing hospitalization and 38.3% permanently discontinuing ICI treatment.

While 85% of patients used GCs, 58.3% and 53.3% of them were deemed GC-refractory and required second-line immunomodulatory therapy, respectively. Despite these challenges, 33.3% achieved complete remission and 51.7% partial remission. The study found that the strongest predictor of the need for second-line systemic therapy was male sex.

Notably, 53.3% of patients required immunomodulatory therapy beyond GCs. The authors emphasize that the therapeutic demand for rh-irAEs, particularly in a rheumatologist-referred setting, is greater than previously reported.