Adverse Effects of Immune Checkpoint Therapy in Cancer Patients Visiting the Emergency Department of a Comprehensive Cancer Center

Study objective: Cancer immunotherapy is evolving rapidly and is transforming cancer care. During the last decade, immune checkpoint therapies have been developed to enhance the immune response; however, specific adverse effects related to autoimmunity are increasingly apparent. This study aims to fill the knowledge gap related to the spectrum of immune-related adverse effects among cancer patients visiting emergency departments (EDs). Methods: We performed a retrospective review of patients treated with immune checkpoint therapy who visited the ED of a comprehensive cancer center between March 1, 2011, and February 29, 2016. Immune-related adverse effects from the ED visits were identified and profiled. We analyzed the association of each immune-related adverse effect with overall survival from the ED visit to death. Results: We identified 1,026 visits for 628 unique patients; of these, 257 visits (25.0%) were related to one ormore immune-related adverse effects. Diarrhea was the most common one leading to an ED visit. The proportions of ED visits associated with diarrhea, hypophysitis, thyroiditis, pancreatitis, or hepatitis varied significantly by immune checkpoint therapy agent. Colitis was significantly associated with better prognosis, whereas pneumonitis was significantly associated with worse survival. Conclusion: Cancer patients treated with ipilimumab, nivolumab, or pembrolizumab may have a spectrum of immunerelated adverse effects that require emergency care. Future studies will need to update this profile as further novel immunotherapeutic agents are added.