Association of efficacy and adverse events of special interest of avelumab in the JAVELIN solid tumor and JAVELIN Merkel 200 trials.

3057Background: Immune checkpoint inhibitors (ICIs) are associated with unique adverse events of special interest (AESI), including infusion-related reactions (IRRs) and immune-related AEs (irAEs). It has been observed that patients (pts) responding to treatment might have a higher likelihood of AEs, potentially due to longer treatment duration. Understanding the association between AESIs and efficacy outcomes may improve the assessment of benefit/risk and thus aid in informed treatment decisions. Methods: We pooled and analyzed efficacy/safety data from NCT01772004 and NCT02155647. We performed an association analysis between response and IRRs. The association of efficacy and irAEs was analyzed using approaches that accounted for time dependency: Cox models analyzed overall survival under consideration of time-varying indicators for irAEs; multistate models were used to gain insight into underlying mechanisms. Results: 1783 pts were included in this analysis. 25.5% of pts had ≥ 1 IRR; 0.7% of pts had a g...