Treatment of metastatic melanoma with anti-PD-1 and anti-LAG-3 in a kidney transplant recipient.

Immune checkpoint inhibitors (ICI) have quickly emerged as standard therapy in multiple cancers, yet their application in organ transplant recipients (OTRs) remains challenging due to risk of graft rejection. In this case, report, we highlight the successful use of a lymphocyte activation gene 3 (LAG-3) inhibitor, relatlimab, in combination with nivolumab (a programmed cell death protein 1 [PD-1] inhibitor) for the treatment of metastatic melanoma in a kidney transplant recipient. The patient developed a complete metabolic response to therapy. LAG-3 expression was notably positive in the renal graft, but negative in the metastatic melanoma tumor tissue. Although the outcome resulted in rapid renal graft rejection, this underscores the need for further research into LAG-3's dual role in cancer therapy and allograft rejection in organ transplant recipients.