INTRODUCTION: [177Lu]Lu-PSMA-617 (177Lu-PSMA-617) plus protocol-permitted standard of care (SoC) prolonged overall survival (OS) and radiographic progression-free survival (rPFS) versus SoC in patients with PSMA-positive metastatic castration-resistant prostate cancer (mCRPC) in the phase 3 VISION study, plus beneficial effects on symptomatic skeletal events (SSEs) and health-related quality of life (HRQoL).
METHODS: Post hoc analyses used the full analysis set (FAS) from VISION (N = 831) overall and by randomized treatment arm (177Lu-PSMA-617 plus SoC, n = 551; SoC, n = 280). Correlations were determined between OS and rPFS, and between rPFS or OS and time to SSE or to worsening HRQoL (Functional Assessment of Cancer Therapy – Prostate [FACT-P] and EQ-5D-5L). Correlation analyses used an iterative multiple imputation copula-based approach (correlation coefficients [rho] < 0.3 were defined as weak; ≥ 0.3 and < 0.5 as mild; ≥ 0.5 and < 0.7 as moderate; ≥ 0.7 as strong).
RESULTS: In the overall population, rPFS correlated strongly with OS (rho ≥ 0.7). Correlations between rPFS or OS and time to SSE without death were weak or mild. Time to worsening in FACT-P total score, emotional and physical well-being domains correlated mildly or moderately with rPFS and moderately with OS. Correlation coefficients for time to worsening EQ-5D-5L scores were mild-to-moderate for both rPFS and OS. Correlation coefficients were similar between treatment arms.
CONCLUSIONS: In this analysis of the VISION study rPFS correlated strongly with OS but not time to SSE or worsening HRQoL. These findings require further investigation.
