Immune-related adverse events during adjuvant therapy with pembrolizumab for stage III melanoma are associated with longer recurrence-free survival, according to a secondary analysis of trial data.

Among more than 1000 patients treated in the EORTC 1325/KEYNOTE-054 trial with the anti-PD-1 agent pembrolizumab (Keytruda), those who had an immune-related adverse event were significantly more likely to survive longer without recurrence, compared with patients not having events.

Dr Stefan Suciu, from the European Organisation for Research and Treatment of Cancer, in Brussels, and colleagues, analysed data from adults participating in the double-blind trial, who received 200mg of pembrolizumab or placebo every three weeks for a total of 18 doses for about a year or until disease recurrence, unacceptable toxic effects or withdrawal from the study.

Among the immune-related adverse events considered were endocrine, pneumonitis/interstitial lung disease, sarcoidosis, vitiligo, severe skin reaction, colitis, pancreatitis, hepatitis, nephritis, uveitis, myositis and/or myocarditis.