A case report of using nivolumab for a malignant melanoma patient with rheumatoid arthritis.

The use of antibodies against programmed cell death 1 (PD-1), which block inhibitory T cell checkpoints, is a promising new therapy for advanced malignant melanoma and NSCLC. However, patients with autoimmune diseases were excluded at the clinical trial using such immune checkpoint inhibitor, because of the possibilities to worsen an adverse event of the autoimmune disease. Thus, the efficacy and toxicity of nivolumab using such cases have not been reported yet. A 70-year-old woman with bone and duodenal metastasis of primary mucosal melanoma with complications of the rheumatoid arthritis was treated with nivolumab. After 4 weeks injection of nivolumab, bone metastasis was diminished. After receiving six courses of nivolumab therapy, she maintained a complete response for 9 months, without rheumatic exacerbation or drug-related adverse events. Establishment of the biomarker of the effect prediction of the PD-1 antibody, the adverse event prediction will be important in future.