Comparison of Outcomes Between Therapeutic Combinations Based on Immune Checkpoint Inhibitors or Tyrosine Kinase Inhibitor Monotherapy for First-Line Therapy of Patients with Advanced Renal Cell Carcinoma Outside of Clinical Trials: A Real-World Retrospective Multi-Institutional Study

BackgroundClinical trials have demonstrated the superior efficacy of immune checkpoint inhibitor (ICI)-based combination therapy over sunitinib, a multi-target tyrosine kinase inhibitor (TKI), in patients with advanced renal cell carcinoma. However, such benefits have not been elucidated in populations outside of clinical trials.MethodsWe retrospectively evaluated data from 467 patients with advanced renal cell carcinoma who received ICI-based combination therapy or TKIs, as first-line therapy. Clinical outcome was compared between ICI-based combination therapy and TKIs in each population divided according to trial eligibility.ResultsAmong 152 patients treated with ICI-based combination therapy and 315 patients treated with TKIs, 76 (50.0%) and 156 (49.5%) were trial ineligible, respectively. Overall survival (p = 0.0072) and objective response rate (p < 0.0001) were significantly higher in ICI-based combination therapy than in TKIs, but progression-free survival was comparable (p = 0.681). In the trial-eligible population, overall survival was longer (p = 0.0906) and the objective response rate was significantly higher (p = 0.0124) in ICI-based combination therapy than in TKIs. In the trial-ineligible population, overall survival (p = 0.0208) and objective response rate (p = 0.0006) were significantly higher with ICI-based combination therapy than with TKIs. A multivariate analysis also showed that ICI-based combination therapy was independently associated with prolonged overall survival (hazard ratio, 0.47; p = 0.0016). Regardless of trial eligibility, progression-free survival did not differ between ICI-based combination therapy and TKIs (trial eligible: p = 0.287; trial ineligible: p = 0.0708).ConclusionsThe present study, using real-world data, provides evidence indicating the therapeutic benefit of ICI-based combination therapy over TKIs for advanced renal cell carcinoma was more statistically significant in the trial-ineligible population than in the trial-eligible population.