LAUSR

Introduction: We investigated the efficacy and safety of every-other-day dosing of sunitinib for the treatment of metastatic renal cell carcinoma (mRCC) with extended follow-up and the impact of immune checkpoint inhibitor (ICI) drugs. Methods: Thirty-two patients received standard dosing treatment (standard group), and 32 received every-other-day treatment (experimental group). Efficacy endpoints included progression-free survival (PFS), overall survival (OS), and objective response rate. We also analyzed the clinical course of patients treated with nivolumab after sunitinib. Results: The minimum follow-up was 42 months. Median PFS and OS were significantly longer in the experimental group compared with the standard group (27.6 vs. 6.2 and 87.1 vs. 24.6 months, respectively). The incidence of dose interruption of sunitinib caused by adverse events was significantly lower in the experimental group than in the standard group (28.1% vs. 56.3%, p = 0.042). Multivariate analysis showed that every-other-day dosing was a significant independent prognostic factor (p = 0.038), although nivolumab use was not (p = 0.232). Twelve patients were treated with nivolumab after sunitinib, and patients who did not respond to nivolumab tended to respond to pretreatment sunitinib for a long period. Discussion/Conclusion: Long-term follow-up confirmed the efficacy and safety of every-other-day dosing of sunitinib for mRCC patients in the ICI era.