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

Abstract

Background: Clinical 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.

Methods: We 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.

Results: Among 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).

Conclusions: The 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.