Background Immune checkpoint inhibitors (ICI) have demonstrated remarkable efficacy as cancer therapeutics, however, their use remains limited due to the development of immune related adverse events (irAEs). Immune related enterocolitis (irEC) is among the most common severe irAEs leading to the discontinuation of ICIs. Inhibitors of tumor necrosis factor alpha (anti-TNFα) have been used to treat irEC. Recent animal studies have shown that concurrent treatment with anti-TNFα and ICIs improves tumor responses and decreases colitis severity. This approach has not yet been studied in prospective trials in humans. Here we describe, for the first time, the outcomes of patients who were treated concurrently with anti-TNFα and one or two ICIs.

Case presentations Five patients with different primary malignancies were treated with ipilimumab/nivolumab (2 patients), pembrolizumab (1 patient), ipilimumab (1 patient), or cemiplimab (1 patient). All patients developed irEC within 40 days of their first ICI dose. The patients presented with a combination of upper and lower gastrointestinal symptoms and subsequently underwent upper endoscopy and/or lower endoscopy. Endoscopy results demonstrated a spectrum of acute inflammatory changes across the gastrointestinal tract. Steroid therapy was used as first line treatment. To prevent prolonged steroid use and recurrence of gastrointestinal inflammation after resumption of cancer therapy, patients were treated concurrently with infliximab and ICI. Patients tolerated further ICI therapy with no recurrence of symptoms. Repeat endoscopies showed resolution of acute inflammation and restaging imaging showed no cancer progression.

Conclusions Concurrent treatment with anti-TNFα and ICI appears to be safe, facilitates steroid tapering, and prevents irEC. Prospective clinical trials are needed to assess the outcomes of this treatment modality.