No abstract

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Immune checkpoint inhibitors (ICIs) and radiotherapy (RT) combinations for various metastatic cancers are increasingly utilized, yet the augmentation of anti-cancer immunity including distant tumor responses by RT remains ill-characterized. Immunosuppressive tumor microenvironments and defective anti-tumor immune activation including immune-related adverse events (irAEs) likely limit dramatic immuno-radiotherapy combinations, though it remains unclear which immune characteristics mediate dramatic systemic tumor regression in only a small subset of patients. Moreover, the efficacy of ICI treatment in patients receiving immunosuppressive therapies for autoimmune conditions or irAEs is convoluted, yet clinically valuable. Here, we report a case of a 75-year-old man with myasthenia gravis and metastatic melanoma who experienced complete and durable systemic regression after receiving pembrolizumab and single-lesion RT while on prednisone for myasthenia gravis prophylaxis and vedolizumab for immune-mediated colitis after previously experiencing mixed response on pembrolizumab monotherapy. We discuss the potential paradoxical effects and clinical considerations of immunosuppressive regimens in patients with underlying autoimmune disease or adverse immune reactions while receiving immuno-radiotherapy combinations.

No abstract