Survival and prognosis of individuals receiving programmed cell death 1 inhibitor with and without immunologic cutaneous adverse events.

Background: The treatment response to new immunotherapy in advanced melanoma patients remains varied between individuals. Immune-related cutaneous side effects might have prognostic value.

Objective: To determine whether development of ≥1 of the 3 immune-mediated cutaneous events (eczema, lichenoid reaction, or vitiligo-like depigmentation) is associated with improved progression-free survival.

Methods: A cohort study of adults with stage IIIC-IV melanoma treated with pembrolizumab or nivolumab during May 1, 2012-February 1, 2018, at Westmead Hospital, Sydney, Australia. Treatment response was based on iRECIST version 1.1.

Results: In total, 82 patients of an average age of 59.9 years were included. Median follow-up was 40.7 months; 33 patients had ≥1 target skin reaction. Skin reactions developed in one-third of individuals by 6 months. At any given time, the instantaneous risk of disease progression and death was lower for individuals who had ≥1 cutaneous adverse event (CAE) develop. Compared with individuals with no CAE, the hazard ratio for disease progression and death for individuals who had ≥1 CAE develop was 0.46 (95% confidence interval 0.23-0.91; P = .025) by the time-dependent Cox proportional hazards model.

Limitations: Single-center study.

Conclusion: This study demonstrates an association between the development of ≥1 of 3 CAEs and improved progression-free survival in this cohort of patients.