Xtandi plus androgen deprivation therapy reduced the risk of death in the phase III PROSPER trial evaluating Xtandi (enzalutamide) plus ADT versus placebo plus ADT in men with non-metastatic castration-resistant prostate cancer.
Xtandi and ADT reduced risk of death by 27% (n=1,401; hazard ratio [HR]=0.73; [95% confidence interval [CI]: 0.61-0.89]; p=0.001) compared to placebo plus ADT. The median OS was 67.0 months (95% CI: 64.0 to not reached) for men who received Xtandi plus ADT compared to 56.3 months (95% CI: 54.4 to 63.0) with placebo plus ADT. OS was a key secondary endpoint of the trial.
Xtandi is sponsored by Pfizer Inc. and Astellas Pharma Inc.
These data were simultaneously published online in the New England Journal of Medicine and presented during the virtual scientific program of the 2020 ASCO annual meeting (Abstract #5515).
In findings published in the New England Journal of Medicine in 2018, the PROSPER trial met its primary endpoint of metastasis-free survival, demonstrating a significant reduction in the risk of developing metastasis or death with Xtandi plus ADT compared to ADT alone in men with nmCRPC (HR=0.29 [95% CI: 0.24-0.35]; p<0.001). MFS was measured as the time from patients entering the trial until their cancer was radiographically detected as having metastasized, or until death, within 112 days of treatment discontinuation.
