Clinical Outcomes of First-line Sunitinib Followed by Immuno-oncology Checkpoint Inhibitors in Patients With Metastatic Renal Cell Carcinoma

BackgroundThe present retrospective, longitudinal cohort study assessed the association between the first-line sunitinib treatment duration and clinical outcomes with second-line immuno-oncology (IO) therapy among patients with metastatic renal cell carcinoma (mRCC).Patients and MethodsA total of 161 patients with mRCC who had been treated with first-line sunitinib and subsequent IO therapy from select International mRCC Database Consortium centers were included. The overall survival, time to next therapy, time to treatment discontinuation, and real-world physician-assessed best response measured from IO therapy initiation were analyzed and compared between patients treated with first-line sunitinib for ≥ 6 months and those treated for < 6 months.ResultsThe 116 patients treated with sunitinib for ≥ 6 months tended to be older and to have a better International mRCC Database Consortium risk than the 45 patients treated for < 6 months (favorable, 36% vs. 8%, P = .001; intermediate, 59% vs. 70%, P = .21; poor, 5% vs. 22%, P = .007). The receipt of sunitinib for ≥ 6 months versus < 6 months was associated with longer survival (hazard ratio HR], 0.42; 95% confidence interval CI], 0.21-0.87; P = .02). No significant association was observed between the first-line sunitinib duration and second-line IO outcomes, including the time to next therapy (HR, 0.89; 95% CI, 0.52-1.51; P = .66), time to treatment discontinuation (HR, 0.85; 95% CI, 0.54-1.34; P = .49), and tumor response (odds ratio, 0.73; 95% CI, 0.22-2.49; P = .62).ConclusionsWe found no statistically significant association between the first-line sunitinib duration and clinical outcomes with second-line IO therapy. Patients receiving first-line sunitinib for ≥ 6 months compared with < 6 months was associated with better overall survival, although potential unadjusted confounders could have been present. These findings support the paradigm that previous therapy will not dictate the effectiveness of subsequent immunotherapy.