Successful Treatment of an Immune-Mediated Colitis Induced by Checkpoint Inhibitor Therapy in a Patient with Advanced Melanoma.

Immune checkpoint inhibitors (ICIs) have been used as immunotherapeutic agents in several malignancies because of their ability to modify the T cell-mediated response against tumor cells. Dual checkpoint inhibition improves remission rates in patients with metastatic melanoma compared to monotherapy. However, a higher incidence of toxicity, including immune-related colitis, has been reported before. A 54-year-old female was diagnosed with malignant melanoma on her left upper arm. Because of progressive metastatic disease, a rescue therapy with nivolumab (Opdivo®) 1 mg/kg and ipilimumab (Yervoy®) 3 mg/kg was initiated and a clinical and radiological remission was achieved. Two weeks after completing the third cycle of the ICI therapy, the patient presented with persistent hemorrhagic diarrhea, nausea and abdominal pain. A diagnostic colonoscopy revealed multiple ulcerative lesions and hemorrhagic colitis of the sigmoid and rectum. Due to the ongoing treatment with nivolumab and ipilimumab, the diagnosis of a checkpoint inhibitor-induced colitis was made and immunosuppression with local and systemic steroids, such as mesalazine was initiated. In order to achieve a long-lasting steroids reduction, we decided to start with infliximab (Remicade® 5 mg/kg body weight i.v. every 2 weeks). Clinical remission was achieved and prednisolone could be subsequently discontinued. Infliximab, in combination with mesalazine, could successfully induce a long-lasting remission without steroids. The treatment of ICI-induced colitis did not lead to a reoccurrence of malignant melanoma after 2 years of follow-up.