Successful use of cemiplimab in a high immunologic risk kidney transplant recipient with metastatic squamous cell carcinoma.

The widespread use of immunotherapy in the management of cancers has led to improved overall survival and progression free survival. Due to increased risk of allograft rejection, organ transplant recipients are often excluded in clinical trials or offered immunotherapy only as salvage therapy. We report a case of successful use of Cemiplimab, an immune checkpoint inhibitor, in a high immunologic risk kidney transplant recipient who was diagnosed with metastatic squamous cell carcinoma (SCC) twenty-five months post-transplant. He started Cemiplimab five months post diagnosis of SCC, as third line therapy, after demonstrating progression of metastatic skull-based disease on prior lines of therapy. His maintenance immunosuppression was changed from triple immunosuppression with tacrolimus, mycophenolate and prednisone to sirolimus with a high trough target of 10-15 ng/mL and steroid therapy. He tolerated the high sirolimus trough and continued on Cemiplimab for six months with clinically stable allograft function and a good quality of life. Notably, he demonstrated response of his previously chemotherapy refractory metastatic disease. He passed away from radiation necrosis of the brain at sixty-eight months post-transplant.