Serious immune‐related upper gastrointestinal toxicity of immune checkpoint inhibitors: a multicenter case series

Immune checkpoint inhibitors (ICI) improve the prognosis of many cancers but cause immune-related adverse events (IrAEs). Limited data are available on upper gastrointestinal (UGI) IrAEs. We describe the clinical characteristics, prognosis, and efficacy of medical therapy in patients with UGI IrAEs.This is a retrospective, multicenter cohort study of patients with UGI symptoms and moderate to severe endoscopic UGI lesions, occurring after ICI. Efficacy of induction medical therapy and at the most recent follow-up was assessed.Forty patients were included; of these, 34 (85%) received anti-PD(L)1, either alone (n = 24) or combined with anti CTLA-4 (n = 10). Eighteen patients (45%) had concomitant enterocolitis. All patients had severe endoscopic lesions (erosions, ulcerations, hemorrhage, or necrotic lesions). Three patients who received an inefficient initial medical treatment had a complicated course: One patient died of enterocolitis, one had a pneumomediastinum, and one developed an ulcerated stricture of the pylorus. Thirty-five patients (88%) were treated with corticosteroids; 28 patients (80%) responded, and 20 (57%) reached clinical remission. Eight patients were treated with infliximab, and six responded (75%). After a median follow-up of 11 months, 36 patients (90%) were in corticosteroid-free clinical remission for their UGI symptoms. Endoscopic lesions persisted in 68% of patients.ICI cause severe UGI IrAEs, which are associated with enterocolitis in approximately half of the patients. Most patients with UGI IrAEs respond to corticosteroids or infliximab. These data support the recommendation to treat these patients without delay and in the same way as those with enterocolitis.