Higher SIT doses reduce new immune-related adverse events after ICI-induced colitis treatment

New immune-related adverse events (irAEs) start to appear more than 6 months following completion of selective immunosuppressive therapy (SIT) agents, such as infliximab and vedolizumab, for initial colitis events, reports a study.

Severe diarrhoea grade and a higher number of SIT infusions are associated with a lower incidence of irAEs. However, the type of SIT or individual dosage of infliximab appears to have no influence on the occurrence of subsequent irAEs.

A retrospective chart review was conducted in adult patients who had a diagnosis of immune checkpoint inhibitor (ICI)-mediated colitis IMC) with SIT at a tertiary cancer centre from February 2013 through October 2021. The authors obtained and analysed the patients’ clinical courses, treatments, and outcomes of new irAEs after SIT.

Of the 156 patients included, 67.3 percent were male, 44.8 percent had melanoma, and 43.5 percent received anti-PD1/L1 ICIs. In terms of IMC treatment, 51.9 percent received infliximab and 37.8 percent received vedolizumab. Twenty-six patients (16.6 percent) continued treatment with ICI following their colitis event.

Notably, a new irAE developed in 25 patients (16 percent) after receiving SIT. The most common new irAE involved the skin (44 percent), most of which (60 percent) were treated with steroids.

Higher diarrhoea grade (p=0.038) and two or more doses of SIT (p=0.05) were predictive of a lower incidence of irAEs after SIT. On the other hand, the type of SIT or individual dosage of infliximab did not influence the occurrence of subsequent irAEs.

“ICIs can cause irAEs such as colitis,” the authors said. “IrAEs can be managed by SIT agents such as infliximab and vedolizumab.”