Baseline geriatric 8 (G8) screening tool to predict overall survival in metastatic urothelial carcinoma treated with immune checkpoint inhibitors.

e16575 Background: Checkpoint inhibitors (CPI) blocking PD-1 or PD-L1 are a mainstay in the treatment of metastatic urothelial cell carcinoma (mUC). Due to the high bar for clinical trial participation, older patients are underrepresented in trials resulting in FDA-approved therapies that are not always representative of real-world patients. The G8 questionnaire is an 8-question screening tool designed to assess frailty in older adults and alert to the need for geriatric assessment. We investigated the ability of the G8 score to predict clinical outcomes in patients with mUC treated with CPIs. Methods: We performed a retrospective analysis of patients with mUC treated with CPIs in any line of treatment at Winship Cancer Institute between 2016-2019. We collected demographic data, patient and disease characteristics, and immune-related adverse events (irAE). A baseline G8 score was evaluated using past clinic notes from providers, social workers, and dietitians. The G8 incorporates measures assessing food intake, weight loss, mobility, neuropsychological conditions, BMI, polypharmacy, self-assessed health, and age. A score of ≤ 14 suggests potential geriatric vulnerability. Progression-free survival (PFS) and overall survival (OS) were measured from the start of CPI until death or clinical or radiographic progression, respectively. The survival association with the G8 score was analyzed using univariate (UVA) and multivariable (MVA) analyses by the Cox proportional hazard model and Kaplan-Meier method. irAEs association was handled by logistic regression. Results: A total of 48 patients with a median age of 73.5 years were analyzed with 66.7% male 75% white. 70.8% of patients had a baseline G8 suggesting geriatric vulnerability despite 74.4% of patients being scored as having an ECOG score of 0-1. An impaired G8 score at CPI initiation was associated with an increased risk of death but not progression on both UVA and MVA. The association between lower rates of irAEs in patients with impaired G8 scores approached statistical significance (Table). The median OS in Kaplan-Meier analysis for patients with an impaired G8 score was significantly lower (6.8 vs 14 months, p=0.0110) but median PFS was comparable (2.5 vs 3.4 months, p=0.4237) to those with a normal G8. Conclusions: These results indicate that the G8 screening tool may be a useful prognostic tool in mUC patients when planning treatment with a CPI, however should be validated with larger cohort studies. [Table: see text]