P1-154Various immuno-related adverse events after IPI+NIVO therapy; a case report of metastatic choroidal melanoma

Abstract Background Choroidal melanoma with metastasis is known to have a poor prognosis with no established standard therapy. Recently there are some case reports that combination therapy of IPI and NIVO is effective, but with high incidence of immune-related adverse events (irAE). Case presentation A 53-year-old man presented with choroidal melanoma of the right eye and underwent stereotactic radio surgery but eighteen months later developed diffuse hepatic metastases. He was treated with combination therapy of IPI and NIVO, but he developed hyposalivation from the next day of first administration, and grade 3 hepatic disorder after 2 cycles. After 3 days administration of mPSL 125mg followed by PSL 0.5mg/kg, his hepatic enzymes normalized, then we started steroid tapering. At the dose of 30mg, he developed grade 4 Stevens-Johnson syndrome, for which 3 days pulse therapy of mPSL 1mg was effective. We re-escalated PSL to 1mg/kg and tapered carefully. At the dose of 15mg, MRI showed progression of liver metastasis. We decided to resume nivolumab monotherapy three months after termination of IPI+NIVO therapy, but it resulted in grade 3 diarrhea. Lower gastrointestinal endoscopy found seemingly normal mucosa, but histological examination showed inflammatory cell infiltration with hemorrhage, which means irAE. Now he is continuing steroid therapy at 15mg of PSL. Conclusion Our patient developed various irAEs after IPI+NIVO therapy for metastatic choroidal melanoma. Each irAEs responded to corticosteroid therapy, but unexpected severe irAEs occurred even with high dose steroid. As a result, prolonged steroid therapy is often needed to control various irAEs, and in those cases, we have to take extra attention to adverse events of steroids such as opportunistic infections.