The safety of pembrolizumab in metastatic melanoma and rheumatoid arthritis.

Immunotherapy has been in use for the treatment of melanoma since a very long time, but only recently have the cytotoxic T-lymphocyte antigen-4 (CTLA-4) antibody ipilimumab and programmed cell death-1 inhibitors such as nivolimumab and pembrolizumab been shown to induce marked improvements in survival in patients with metastatic melanoma. An important concern arises in terms of the safety of the use of these agents in patients with autoimmune diseases, solid organ transplant recipients on immunosuppression, patients with a history of previous hepatitis B or C, and patients with HIV infections as these patients were excluded from pivotal immunotherapy studies. Here, we report on the safety and efficacy of pembrolizumab in a melanoma patient with multiple medical problems including poorly controlled rheumatoid arthritis and we review the available literature on the use of immunotherapy and autoimmune diseases. The weight of evidence suggests that these patients should be offered the opportunity to benefit from immune check point inhibitors, with drugs targeting programmed cell death-1 being preferred. More research is required to study the long-term effects of immunotherapy on patients with autoimmune diseases.