The effect of immune checkpoint inhibitor combination therapies in metastatic renal cell carcinoma patients with and without previous cytoreductive nephrectomy: A systematic review and meta-analysis

Background: Recently, immune checkpoint inhibitor (ICI)-combination therapies have radically altered the treatment landscape in metastatic renal cell carcinoma (mRCC). No phase 3 trials have assessed the impact of cytoreductive nephrectomy (CN) for efficacy in mRCC patients treated with ICI-combination therapy. We aimed to assess the role of ICI-combination therapy based on CN status. Methods: Multiple databases were searched for articles published until June 2021. Studies comparing overall and/or progression-free survival (OS/PFS) in mRCC patients treated with ICI combination-therapy were deemed eligible. Results: Six studies met the eligibility criteria. ICI-combination therapy was associated with significantly better OS/PFS than sunitinib in patients who had undergone CN (hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.59-0.77/HR, 0.57; 95% CI, 0.44-0.74, respectively; both P < 0.001), and in those who had not (HR, 0.69; 95% CI, 0.57-0.85/HR, 0.63; 95% CI, 0.52-0.77, respectively; both P < 0.001). Although the OS and PFS benefits of ICI-combination therapy were larger in those undergoing CN, the HR for OS and PFS indicated that ICIcombination therapy's treatment effect did not differ substantially with or without CN. In network meta-analyses, nivolumab plus cabozantinib was the most effective regimen in those undergoing CN, and pembrolizumab plus lenvatinib for those not undergoing CN. Conclusion: The effect of ICI combination therapy did not differ between mRCC patients undergoing and not undergoing CN. As each ICI combination regimen varied widely in its effect in patients undergoing and not undergoing CN, CN may contribute to better treatment decision-making for ICI-combination therapy recipients.