Contact immunotherapy enhances the therapeutic effects of nivolumab in treating in‐transit melanoma: Two cases reports

Because nivolumab significantly prolongs survival in patients with metastatic melanoma, enhancing its antitumor immune response is of great interest to dermato‐oncologists. In this report, we describe two cases of metastatic melanoma successfully treated with nivolumab in combination with contact immunotherapy, using contact sensitizing agents, such as squaric acid dibutylester and diphencyprone. In addition, immunohistochemical staining supported one of the possible mechanisms of this combination therapy. Our present cases suggested a possible therapy for metastatic melanoma using nivolumab in combination with contact immunotherapy.