An Abscopal Response to Radiation and Ipilimumab in a Patient with Metastatic Non–Small Cell Lung Cancer

A posteriori evidence suggests that radiotherapy to a targeted tumor can elicit an immune-mediated abscopal (ab-scopus, away from the target) effect in non-targeted tumors, when combined with an anti-cytotoxic T-lymphocyte antigen-4 monoclonal (CTLA-4) antibody. Concurrent radiotherapy and ipilimumab (a human monoclonal anti-CTLA-4 antibody) induced immune-mediated abscopal effects in poorly immunogenic pre-clinical tumor models and metastatic melanoma patients. However, no such reports exist for patients with metastatic lung adenocarcinoma. We report the first abscopal response in a treatment-refractory lung cancer patient treated with radiotherapy and ipilimumab. A post-treatment increase in tumor-infiltrating cytotoxic lymphocytes, tumor regression, and normalization of tumor markers was observed. One year after treatment with concurrent radiotherapy and ipilimumab the patient is without evidence of disease.