Association between immune-related adverse events and prognosis in patients treated with immune checkpoint inhibitors in melanoma: A surrogacy analysis

BackgroundImmune checkpoint inhibitors (ICI) represent a breakthrough in oncology in terms of prognosis and safety. They now constitute a cornerstone in the management of metastatic melanoma. However, a new kind of adverse event called immune-related adverse events (irAE) has emerged. These irAE could be conceptually considered as an indicator of the antitumoral immune response, but the association between irAE and prognosis is still a matter of debate.ObjectiveThe purpose of this study was to investigate the association between the overall survival (OS) and the prevalence of irAE in melanoma.MethodsMEDLINE/PubMed, WebofScience, ClinicalTrials, and WHOTrials databases were searched to identify phase 3 randomized controlled trials (RCT) assessing ICI in melanoma and published up to April 2021. A weighted regression was performed to estimate this association according to standard method of surrogacy analysis.ResultsA total of 14 RCT including 7646 patients (median age: 59.3 years) with melanoma were included. All types of ICI were represented (ipilimumab, tremelimumab, pembrolizumab, nivolumab, atezolizumab, as well as ipilimumab and nivolumab combination). irAE were frequent but rarely fatal. The combination of ICI caused more irAE than anti-PD1 (or PDL1) and anti-CTLA4 monotherapies. No relationship was found between the occurrence of irAE and OS (beta coefficient 0.078, R2 3%, p = 0.52), nor between cutaneous irAE and OS (beta coefficient 0.080, R2 6%, p = 0.33).ConclusionAlthough limited by the heterogeneity of ICI included in the regression and the low number of included RCT, the present study suggests an absence of association between irAE and prognosis in melanoma.