Dermatological adverse events under programmed cell death‐1 inhibitors as a prognostic marker in metastatic melanoma

Melanoma is widely treated with programmed cell death‐1 (PD‐1) inhibitors. As part of their anti‐tumor immunity effect, they increase the susceptibility to cutaneous immune‐related adverse events (cIRAE) among other autoimmune effects. To characterize the manifestations of cIRAE in melanoma patients treated with PD‐1 inhibitors, and evaluate the correlation with tumor response. A retrospective study of 95 metastatic malignant melanoma patients treated with PD‐1 inhibitors at the Hadassah Medical Center during 2013–2016. The most common cIRAE was pruritus reported by 39 (41%) patients. All other cIRAE were noted in 34 patients (35.8%), of which the most common cutaneous manifestation was vitiligo, demonstrated in 17 patients (17.9%) followed by various rashes (7.4%, including erythema multiforme, oral lichen planus, photosensitive rash, insect bite‐like reaction, and urticaria), psoriasiform rash (3.2%), bullous pemphigoid (3.2%), and eczema (1%). Interestingly, higher response rates to immunotherapy were demonstrated in patients who developed pruritus (85%) and cIRAE (88%), with lower mortality rates in the cIRAE group (38.2%) versus the non‐cIRAE group (70.5%, p = 0.002). cIRAE are common among malignant melanoma patients treated with PD‐1 inhibitors and may be a marker for favorable prognosis.