Development of Poliosis in Patients Treated With Immunotherapy for Metastatic Cutaneous and Non‐Cutaneous Melanoma

While prior studies have described the development of vitiligo and alopecia among patients with metastatic melanoma undergoing cancer immunotherapy, there are scant reports of secondary poliosis. Here we detail a case series of patients with melanoma who developed poliosis secondary to cancer immunotherapy. A clinical database of melanoma patients treated at the University of Southern California, Norris Comprehensive Cancer Center, from 2018 to 2023 was reviewed to identify patients who developed poliosis during cancer immunotherapy treatment. Patients with both cutaneous and non-cutaneous melanoma (acral and uveal) were included. Cancer immunotherapies included checkpoint inhibitors, bispecifics, and tumor infiltrating lymphocyte (TIL) therapy. Patient characteristics, tumor features (histology, stage), treatment variables, and clinical outcomes were collected for all patients. Immunotherapy-related side effects, including poliosis, were recorded. A total of 10 melanoma patients with poliosis were identified, including 5 women; 8 had stage IV disease. The median duration of immunotherapy treatment was 20 months (range 10-46). Median onset of poliosis was 4 months (range 2-12). Amongst the 10 patients, 9 (90%) remain in continued response to treatment without disease progression at this time. This case series describes 10 melanoma patients who developed poliosis while undergoing immunotherapy, all of whom developed clinical benefit from treatment. This cohort included patients with rare and challenging melanoma subtypes, e.g., acral lentiginous and uveal melanoma. The development of poliosis may portend a positive clinical benefit from these immunotherapy treatments. Further research is necessary to elucidate the underlying mechanisms of immune-mediated melanocyte destruction and depigmentation in melanoma patients receiving immunotherapy.