Clinical outcomes of second-line treatment following prior targeted therapy in patients with metastatic renal cell carcinoma: a comparison of axitinib and nivolumab.

BACKGROUND: Sequential treatment starting with target therapy is still the standard care for metastatic renal cell carcinoma (mRCC), even in the era of immune checkpoint inhibitors. Our objective was to compare the clinical outcomes between axitinib and nivolumab as second-line therapy following prior targeted therapy in mRCC patients. METHODS: We identified 41 patients treated with axitinib and 39 patients treated with nivolumab as a second-line regimen after targeted therapy, and retrospectively compared the treatment efficacy and safety in these patients. RESULTS: The clinical benefit rate of axitinib was significantly higher than that of nivolumab (82.9% versus 56.4%; p = 0.014) and patients who received axitinib tended to show longer progression-free survival (PFS) than those who received nivolumab (10.3 months versus 7.3 months; p = 0.067). There was no difference in the overall survival (OS) of the two groups (both not reached; p = 0.581). The incidence of grade ≥ 3 adverse events (AEs) was similar between the two groups, but one patient in the nivolumab group died due to an immune-related AE. In addition, a Cox proportional hazards model showed that the pre-treatment KPS, the baseline neutrophil-to-lymphocyte ratio (NLR), and an objective response in second-line therapy were significantly associated with PFS, while the pre-treatment KPS, the number of metastatic organs, and an objective response in second-line therapy significantly contributed to the predicted OS. CONCLUSIONS: Although the prognosis did not differ markedly between the two groups, axitinib resulted in a better tumor response rate. Further randomized prospective studies are needed for the ideal order of this sequential treatment.