Modified Glasgow Prognostic Score associated with survival in metastatic renal cell carcinoma treated with immune checkpoint inhibitors

Background The modified Glasgow Prognostic Score (mGPS) is a composite biomarker that uses albumin and C reactive protein (CRP). There are multiple immune checkpoint inhibitor (ICI)-based combinations approved for metastatic renal cell carcinoma (mRCC). We investigated the ability of mGPS to predict outcomes in patients with mRCC receiving ICI. Methods We retrospectively reviewed patients with mRCC treated with ICI as monotherapy or in combination at Winship Cancer Institute between 2015 and 2020. Overall survival (OS) and progression-free survival (PFS) were measured from the start date of ICI until death or clinical/radiographical progression, respectively. The baseline mGPS was defined as a summary score based on pre-ICI values with one point given for CRP>10 mg/L and/or albumin<3.5 g/dL, resulting in possible scores of 0, 1 and 2. If only albumin was low with a normal CRP, no points were awarded. Univariate analysis (UVA) and multivariate analysis (MVA) were carried out using Cox proportional hazard model. Outcomes were also assessed by Kaplan-Meier analysis. Results 156 patients were included with a median follow-up 24.2 months. The median age was 64 years and 78% had clear cell histology. Baseline mGPS was 0 in 36%, 1 in 40% and 2 in 24% of patients. In UVA, a baseline mGPS of 2 was associated with shorter OS (HR 4.29, 95% CI 2.24 to 8.24, p<0.001) and PFS (HR 1.90, 95% CI 1.20 to 3.01, p=0.006) relative to a score of 0; this disparity in outcome based on baseline mGPS persisted in MVA. The respective median OS of patients with baseline mGPS of 0, 1 and 2 was 44.5 (95% CI 27.3 to not evaluable), 15.3 (95% CI 11.0 to 24.2) and 10 (95% CI 4.6 to 17.5) months (p<0.0001). The median PFS of these three cohorts was 6.7 (95% CI 3.6 to 13.1), 4.2 (95% CI 2.9 to 6.2) and 2.6 (95% CI 2.0 to 5.6), respectively (p=0.0216). The discrimination power of baseline mGPS to predict survival outcomes was comparable to the IMDC risk score based on Uno's c-statistic (OS: 0.6312 vs 0.6102, PFS: 0.5752 vs 0.5533). Conclusion The mGPS is prognostic in this cohort of patients with mRCC treated with ICI as monotherapy or in combination. These results warrant external and prospective validation.