Can health-related quality of life (HRQoL) predict conditional survival (CS) in metastatic renal cell carcinoma? Results from a large phase 3 trial.

691Background: In the absence of mature overall survival (OS) endpoints, interim clinical trial data can be used to predict long-term survival in patients (pts) with advanced malignancies and inform trial continuation, treatment preference, and reimbursement decisions. Research shows that HRQoL assessments can be associated with OS, offering potential utility for validated HRQoL scales. We describe a predictive model used to determine the extent to which HRQoL data could predict CS (survival conditional on progression at either 6 or 12 months). Methods: Using pt-level data from a large phase III trial of nivolumab vs everolimus, a simulation approach with a survival random forest algorithm identified factors statistically important in predicting CS from a large number of covariates measured at baseline. Stepwise Cox proportional hazard survival models were fitted using covariates identified as important. Baseline scores and change over time were tested to determine the influence on the predictive power of...