Nivolumab in Resected and Unresectable Metastatic Melanoma: Characteristics of Immune-Related Adverse Events and Association with Outcomes

IrAEs of any grade were observed in 68.2% of patients (101 of 148). Grade III/IV irAEs were infrequent: 3 (2%) had grade III rash, 2 (1.35%) had asymptomatic grade III elevation in amylase/lipase, and 2 (1.35%) had grade III colitis. A statistically significant OS difference was noted among patients with any grade of irAE versus those without (P ≤ 0.001), and OS benefit was noted in patients who reported three or more irAE events (P ≤ 0.001). Subset analyses showed statistically significant OS differences with rash [P = 0.001; HR, 0.423; 95% confidence interval (CI), 0.243-0.735] and vitiligo (P = 0.012; HR, 0.184; 95% CI, 0.036-0.94). Rash and vitiligo also correlated with statistically significant OS differences in patients with metastatic disease (P = 0.004 and P = 0.028, respectively). No significant survival differences were seen with other irAEs (endocrinopathies, colitis, or pneumonitis).

Cutaneous irAEs are associated with improved survival in melanoma patients treated with nivolumab, and clinical benefit should be validated in larger prospective analyses.