Objective Immune checkpoint inhibitor (ICI) colitis is a common side effect of cancer treatment using ICIs that causes morbidity and mortality. Guidelines recommend initial management with high-dose systemic corticosteroids. Second-line management is with selective immunosuppressive therapy (SIT) such as infliximab and vedolizumab. The aim of our study was to assess for factors predicting need for treatment with second-line SIT in patients with ICI colitis. Design/method Two-centre retrospective analysis of adult patients admitted to hospital with ICI colitis between July 2018 and March 2023. Patient baseline characteristics and variables including ICI, histological inflammation, Mayo Endoscopic Score (MES), albumin, C reactive protein and calprotectin were reviewed. Univariable analysis was carried out to identify factors that predicted non-response to steroids. Results 82 patients were included in the analysis, 51 (62.2%) male, median age 71 (IQR 20 years). 28 (34.1%) required SIT. On univariable analysis, calprotectin emerged as a predictor of non-response to steroid therapy and the need to escalate to management with SIT. Receiver operating characteristic analysis identified an optimal cut-off of 620 μg/g to identify those who required second-line SIT (sensitivity 75% (57.6%–92.7%), specificity 77.8% (52.4%–93.6%), accuracy 76.5%, positive predictive value 75% (47.6%–92.7%), negative predictive value 77.8% (52.4%–93.6)). Conclusions Faecal calprotectin can be used as a biomarker to identify patients with ICI colitis who are unlikely to have a successful or sustained response to systemic corticosteroids and require escalation to management with SIT. We have identified an optimal threshold of >620 μg/g. This highlights the possibility of non-invasive testing to assist with guiding therapeutic management.
Crothers-Stomps et al. (Wed,) studied this question.