Immune checkpoint inhibitor associated vitiligo and its impact on survival in patients with metastatic melanoma: an Italian Melanoma Intergroup study

Abstract

BackgroundCheckpoint inhibitors in melanoma can lead to self-immune side-effects such as vitiligo-like depigmentation (VLD). Beyond the reported association with favorable prognosis, there are limited data regarding VLD patient features and their echo on the therapeutic outcomes.MethodsTo assess the association between VLD and a series of clinical and biological features as well as therapeutic outcomes, we built an observational cohort study by recruiting patients who developed VLD during checkpoint inhibitors.ResultsA total of 148 patients from 15 centers (101 men, median age 66 years, BRAF mutated 23%, M1c 42%, Eastern Cooperative Oncology Group (ECOG) status 0/1 99%, normal lactate dehydrogenase 74%) were enrolled. VLD was induced by ipilimumab, programmed cell death-1 (PD-1) inhibitors, and their combination in 32%, 56%, and 12%, respectively. The median onset was 26 weeks and it was associated with other skin and nonskin toxicities in 27% and 28%, respectively. After 3 years of VLD onset, 52% (95% confidence interval 39% to 63%) were progression free and 82% (95% confidence interval 70% to 89%) were still alive. The overall response rate was 73% with 26% complete response. Univariable analysis indicated that BRAF V600 mutation was associated with a better overall survival (P = 0.028), while in multivariable analysis a longer progression-free survival was associated with BRAF V600 (P = 0.093), female sex (P = 0.008), and M stage other than 1a (P = 0.024). When VLD occurred, there was a significant decrease of white blood cell (WBC) count (P = 0.05) and derived WBC-to-lymphocytes ratio (dWLR; P = 0.003). A lower monocyte count (P = 0.02) and dWLR (P = 0.01) were also reported in responder patients.ConclusionsAmong VLD population, some features might help to identify patients with an effective response to immunotherapy, allowing clinicians to make more appropriate choices in terms of therapeutic options and duration.