Association between immune-related adverse event timing and treatment outcomes

The timing of immune-related adverse events (irAE) associated with immune checkpoint inhibitors (ICI) is highly variable. Although the development of irAE has been associated with ICI clinical benefit, how irAE timing influences this association is unknown. We analyzed two independent cohorts including 154 patients with non-small cell lung cancer (NSCLC) treated with PD-1/PD-L1 inhibitors at a single institution (UTSW cohort) and a multi-center cohort of 433 patients with NSCLC who received second-line anti-PD-1/PD-L1 therapy (Global cohort) to assess the association between ICI outcomes and irAE timing. In both cohorts, late-onset irAE occurring more than 3 months after ICI initiation compared to irAE occurring earlier were associated with greater rates of radiographic response (UTSW cohort, 41% versus 28%, P = .26; Global cohort, 60% versus 35%, P = .02), longer progression-free (UTSW cohort, 13.7 versus 5.6 months, P