Effect of First-Line Combination Systemic Therapy on Favorable-Risk Clear Cell Renal Cell Carcinoma: A Retrospective Study

Background/Objectives: For patients with advanced or metastatic clear cell renal cell carcinoma (RCC), combinations of immune checkpoint inhibitors (ICIs) and VEGFR-targeted tyrosine kinase inhibitors (TKIs) are standard first-line therapies. However, the clinical benefit of these regimens in patients with favorable IMDC risk remains unclear. Methods: We retrospectively analyzed 147 patients with favorable-risk metastatic RCC treated with first-line systemic therapy at the Samsung Medical Center between 2019 and 2023. Treatment regimens included TKI monotherapy (n = 110) or ICI–TKI combinations (n = 37). Progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) were evaluated using Kaplan–Meier and Cox regression analyses. Results: At a median follow-up of 46.3 months, the overall median PFS was 20.1 months (95% CI, 14.5–25.7). Median PFS was 26.2 months with ICI–TKI combinations versus 17.0 months with TKI monotherapy (HR 1.32; 95% CI, 0.82–2.12; p = 0.25). In multivariate analysis, TKI monotherapy (HR 14.01; p = 0.002) and liver metastasis (HR 9.17; p < 0.001) were independent predictors of shorter PFS. ORR was significantly higher with combination therapy (68% vs. 46%; p = 0.01). Median OS was not reached in either group, with 3-year OS rates of 89% and 84%, respectively. Conclusions: The findings suggest that even within the favorable-risk population, clinical heterogeneity influences treatment outcomes, emphasizing the need for individualized therapy selection and refined prognostic models.