Cutaneous manifestations induced by check point inhibitors in 120 melanoma patients-The European MelSkinTox study

Checkpoint inhibitors provide an effective approach for the melanoma treatment. They prolong lymphocyte effects, which explains the cytotoxicity underlying immune-related adverse events (IrAEs). Cutaneous IrAEs affect nearly 40% of PD-1i and 50% of CTLA4i-treated patients. Severe cutaneous irAE do not often occur but could be life-threatening and may persist despite treatment discontinuation.

We aimed to investigate cutaneous IrAEs in a cohort of patients treated with ICI across Europe in an effort to characterize the reactions in a real-world, phase IV, post-marketing study using a follow-up questionnaire. Data since November 2016 until March 2021 were obtained from the Melskintox database, a European multicentric biobank dedicated to the follow-up of melanoma and cutaneous adverse events, supported by EADO. The dermatoses reported were pooled into four categories: inflammatory dermatosis, bullous diseases, drug-related eruptions and pigmentary diseases.

Inflammatory benign dermatoses (n = 63) represented the most common group of reactions (52.5%), followed by drug-related eruptions (n = 24, 20%), pigmentary diseases (n = 23, 19.2%) and bullous diseases (n = 10, 8.3%). Grade II (n = 41, 34.2%) are represented by bullous pemphigoid, eczema, hypodermitis, lichenoid eruption, maculopapular rash, pruritus, psoriasis-like rash, urticarial eruption and vitiligo. Grade III (n = 18, 15.0%) are represented by bullous pemphigoid, lichenoid eruption and rashes. Grade IV (n = 2, 1.7%) is only represented by bullous disease. Most cutaneous IrAEs led to immunotherapy continuation (n = 95, 88.0%). CR is associated with more severe the cutaneous irAEs. We report an average time-to-onset of 208 days and some late-onset events.

Our study has characterized the clinical spectrum of cutaneous irAEs, their timing and severity and their relationship with tumour response. Grade I-II cutaneous IrAE are easily managed allowing ongoing anticancer treatment. Severe late-onset cutaneous irAE are not uncommon. A dermatological follow-up helps mitigate the risk of life-threatening adverse events. These findings highlight the importance of oncodermatological involvement in management of patients with melanoma receiving immunotherapy.