Treating metastatic clear-cell renal cell carcinoma: beyond immunotherapy

First-line treatment for metastatic clear-cell renal cell carcinoma patients with intermediate and poor-risk features consists of a combination of immune checkpoint inhibitors (e.g., nivolumab + ipilimumab) or immunotherapy with an anti-vascular endothelial growth factor receptor (VEGFR) drug (e.g., axitinib). The subsequent line of therapy should be determined on the basis of previous treatments and approved drugs available, based on the results of randomized clinical trials. Unfortunately, no phase 3 trial has compared the safety and efficacy of drugs after immunotherapy; thus, drug choice is more empirical than evidence-based. As the tumor may still be anti-VEGFR drug-naïve, a tyrosine kinase inhibitor approved for first line treatment (e.g., sunitinib or pazopanib) may be beneficial. Because this is a second-line treatment, patients could also receive axitinib, cabozantinib, or a combination of lenvatinib and everolimus. The treating physician should choose an appropriate treatment according to the patient's age, comorbidities, and tolerability of previous checkpoint inhibitors, among other considerations. Cases of patients with renal cell carcinoma refractory to checkpoint inhibitor treatment are growing, warranting a review of the activity and safety of target therapies after immunotherapy.