Immune adverse events (irAEs) with adjuvant ipilimumab in melanoma, use of immunosuppressants and association with outcome: ECOG-ACRIN E1609 study analysis

Background The impact of immune-related adverse events (irAEs) occurring from adjuvant use of immunotherapy and of their management on relapse-free survival (RFS) and overall survival (OS) outcomes is currently not well understood.Patients and methods E1609 enrolled 1673 patients with resected high-risk melanoma and evaluated adjuvant ipilimumab 3 mg/kg (ipi3) and 10 mg/kg (ipi10) versus interferon-α. We investigated the association of irAEs and of use of immunosuppressants with RFS and OS for patients treated with ipilimumab (n=1034).Results Occurrence of grades 1–2 irAEs was associated with RFS (5 years: 52% (95% CI 47% to 56%) vs 41% (95% CI 31% to 50%) with no AE; p=0.006) and a trend toward improved OS (5 years: 75% (95% CI 71% to 79%) compared with 67% (95% CI 56% to 75%) with no AE; p=0.064). Among specific irAEs, grades 1–2 rash was most significantly associated with RFS (p=0.002) and OS (p=0.003). In multivariate models adjusting for prognostic factors, the most significant associations were seen for grades 1–2 rash with RFS (p