Anti-PD-1 immunotherapy for the treatment of metastatic urothelial carcinoma in a kidney transplant recipient: a case report.

backgroundImmune checkpoint inhibitor (ICI) therapy has been widely investigated in urothelial carcinoma; however, the utility of ICI therapy in the treatment of organ transplant recipients with metastatic urothelial carcinoma (mUC) is unclear. We herein report the first case of a first-line anti-programmed cell death-1 (anti-PD-1) monotherapy for a kidney transplant patient with mUC. CASE PRESENTATION: A 71-year-old woman who received a kidney transplant in 2003 was diagnosed with urothelial carcinoma in 2018. After operation of the tumor, the patient developed local recurrence at the site of the right kidney and bladder and multiple distant metastases in May 2020. Considering the intolerance of chemotherapy and high tumor mutation burden, we administered the anti-PD-1 agent tislelizumab (200 mg every three weeks). Partial response was achieved after two cycles of therapy and sustained until 18th cycles. There were no signs of kidney graft rejection. The immunotherapy was temporarily stopped after the 18th course because of a suspicious immune-related pneumonitis and was continued in December 2021.

conclusionsThis case demonstrates the feasibility of safely achieving stable cancer control in a kidney transplant patient with mUC without encountering graft rejection by using single-agent anti-PD-1 treatment.