Impact of immune-related adverse events on survival among patients with head-and-neck squamous cell carcinoma.

Immune-checkpoint inhibitors (ICIs) have revolutionized treatment of metastatic head and neck squamous cell carcinomas (HNSCCs). Our goal was to assess for an association between immune-related adverse events (irAEs) and clinical outcomes for patients on ICIs. We analyzed a cohort of 110 HNSCC patients who received ICI therapy at the University of Virginia. On review, 48% of our patients experienced an irAE with the most common events being hypothyroidism (30%), dermatitis (14%) and hepatitis (11%). Women were more likely to experience irAEs. Treatment interruption/discontinuation occurred in 43% patients with irAEs. Development of irAEs was associated with superior objective response rate (68 vs. 39%,  = 0.009), with a greater rate of CR (17 vs. 5%) and PR (32 vs. 16%). Twelve patients underwent ICI re-treatment following irAE, with 17% attaining a complete disease response, 25% attaining a partial response, 33% achieving stable disease and 25% experiencing disease progression with ICI resumption. Development of irAE was associated with superior objective response rate, with a greater rate of CR and PR. ICI re-treatment following irAE was feasible in a significant proportion of patients and can be attempted in carefully selected patients, given the dearth of second-line therapies for these patients.