Two cases of delayed onset of immune-related adverse events after discontinuation of nivolumab in patients with metastatic renal cell cancer.

Introduction: Delayed onset of immune-related adverse events following immune-checkpoint inhibitor discontinuation is underrecognized because of little available evidence.
Case Presentation: A 50-year-old man with metastatic renal cell carcinoma (Case 1) and 58-year-old woman with renal cell carcinoma and retroperitoneal lymph node metastasis (Case 2) underwent nivolumab therapy. Case 1: Progressive disease forced nivolumab discontinuance after 18 months, and he underwent two courses of tyrosine kinase inhibitor therapy. immune-related adverse events of pneumonitis, hepatitis, and renal dysfunction were diagnosed 142 days after nivolumab discontinuation, and he recovered with immunosuppressive treatment. Case 2: The immune-related adverse event of pneumonitis forced nivolumab discontinuance after 14 months, and two courses of tyrosine kinase inhibitor therapy were administered. The immune-related adverse event of hepatitis was diagnosed 436 days after nivolumab discontinuation, and she recovered with immunosuppressive treatment.
Conclusion: Two patients with delayed onset of immune-related adverse events after nivolumab discontinuation were recovered with immunosuppressive treatment.
Competing Interests: The authors declare no conflict of interest.
(© 2021 The Authors. IJU Case Reports published by John Wiley & Sons Australia, Ltd on behalf of the Japanese Urological Association.)