Ipilimumab and Nivolumab induced steroid-refractory colitis treated with infliximab: A case report.

Background: A variety of immune-modulating drugs are becoming increasingly used for various cancers. Despite increasing indications and improved efficacy, they are often associated with a wide variety of immune mediated adverse events including colitis that may be refractory to conventional therapy. Although these drugs are being more commonly used by Hematologists and Oncologists, there are still many gastroenterologists who are not familiar with the incidence and natural history of gastrointestinal immune-mediated side effects, as well as the role of infliximab in the management of this condition.

Case Summary: We report a case of a 63-year-old male with a history of metastatic renal cell carcinoma who presented to our hospital with severe diarrhea. The patient had received his third combination infusion of the anti-CTLA-4 monoclonal antibody Ipilimumab and the immune checkpoint inhibitor Nivolumab and developed severe watery non-bloody diarrhea the same day. He presented to the hospital where he was found to be severely dehydrated and in acute renal failure. An extensive workup was negative for infectious etiologies and he was initiated on high dose intravenous steroids. However, he continued to worsen. A colonoscopy was performed and revealed no endoscopic evidence of inflammation. Random biopsies for histology were obtained which showed mild colitis, and were negative for Cytomegalovirus and Herpes Simplex Virus. He was diagnosed with severe steroid-refractory colitis induced by Ipilimumab and Nivolumab and was initiated on Infliximab. He responded promptly to it and his diarrhea resolved the next day with progressive resolution of his renal impairment. On follow up his gastrointestinal side symptoms did not recur.

Conclusion: Given the increasing use of immune therapy in a variety of cancers, it is important for gastroenterologists to be familiar with their gastrointestinal side effects and comfortable with their management, including prescribing infliximab.