A case report of cerebral vasculitis induced by ipilimumab with nivolumab in a patient with metastatic renal cell carcinoma

The prognosis of patients with metastatic renal cell carcinoma (RCC) has improved with the introduction of novel combination therapies, including monoclonal antibodies such as ipilimumab (against CTLA-4) with nivolumab (against PD-1). However, these checkpoint inhibitors are associated with a broad spectrum of immune-related adverse events (irAEs). Herein, we report a case of suspected immune-related cerebral vasculitis occurring three weeks after initiation of ipilimumab plus nivolumab in a patient with metastatic not-otherwise-specified (NOS) renal cell carcinoma (RCC). Brain MRI demonstrated multifocal supratentorial cortico-subcortical lesions with diffusion restriction and focal cortical enhancement, compatible with acute to subacute ischemia. In the context of the clinical presentation, exclusion of common stroke mechanisms, and a favorable response to corticosteroids, both clinically and para-clinically with a marked decline in CRP, the findings were considered most consistent with possible immune-related cerebral vasculitis. Three months after only one application of combined immunotherapy, a restaging CT scan showed an objective response in terms of partial remission. However, the metastatic RCC progressed after another 3 months, and the patient received two lines of tyrosine kinase inhibitors (sunitinib and cabozantinib). The patient died due to cancer progression, with an overall survival of 10.5 months. This case report provides experience with the management of possible immune-related cerebral vasculitis in patients with a rare malignancy. Severe cerebral vasculitis requires hospitalization with prompt diagnostic workup and immunosuppressive treatment. Despite the preterm permanent discontinuation of immunotherapy, the patients can benefit from the systemic treatment.