Real-World Survival Outcomes of First-Line Therapies in Patients with Metastatic Clear Cell Renal Cell Carcinoma: A Retrospective Analysis from Two Centres in Saudi Arabia

<b>Background</b>: Metastatic renal cell carcinoma (mRCC) represents a challenging condition characterised by poor prognosis and limited response to chemoradiotherapy. In this retrospective study, we compared the survival outcomes of first-line ICI regimens versus single-agent TKIs in patients with mRCC from two centres in Saudi Arabia. <b>Methods</b>: This study included 84 patients diagnosed with clear cell mRCC between January 2016 and December 2023. Patients were grouped based on treatment regimens. Progression-free survival (PFS) and overall survival (OS) were analysed using Kaplan-Meier curves and Cox proportional hazards regression. <b>Results</b>: The median first-line PFS was 9.7 months (95% CI: 5.3-14.1) for the overall cohort, with no significant difference between the single-agent tyrosine kinase inhibitor (TKI) group (9.4 months; 95% CI: 6.4-12.4), combination ICI group (9.0 months; 95% CI: 0.0-24.9), and single-agent ICI group (21.2 months; 95% CI: 2.6-39.8; <i>p</i> = 0.591). The median OS for the overall cohort was 42.0 months (95% CI: 14.9-69.2), with the single-agent TKI group having a median OS of 33.3 months (95% CI: 0.0-71.7), the combination ICI group, 42.0 months (95% CI: 0.06-84.0), and the single-agent ICI group, 23.0 months (95% CI: 19.2-26.7; <i>p</i> = 0.73). In comparison, the ICI-based combination therapy group exhibited a higher ORR of 41.0% (95% CI: 26.3-57.8%), while the single-agent ICI group had an ORR of 20.0% (95% CI: 3.5-55.8%). Cox regression identified liver metastasis as a significant independent predictor of PFS (HR = 1.8, <i>p</i> = 0.043), while a lower Karnofsky Performance Status was a significant independent predictor of OS (HR = 3.5, <i>p</i> < 0.001). <b>Conclusions</b>: In real-world practice from Saudi Arabia, first-line, single-agent ICI therapy offers promising anti-tumour activity and non-inferior survival outcomes compared to standard ICI-based combinations and single-agent TKIs.