Enzalutamide in patients with high-risk biochemically recurrent prostate cancer according to the European Association of Urology definition: a post hoc analysis of EMBARK.

High-risk biochemical recurrence (BCR) definition varies across clinical studies/practice guidelines. We evaluated metastasis-free survival (MFS) by blinded, independent, central review and safety in EMBARK (NCT02319837) patients defined as high-risk BCR per European Association of Urology (EAU) criteria. Patients post-radical prostatectomy (prostatic-specific antigen doubling time ≤9 months) or post-radiation therapy with a Gleason score > 7, were considered EAU high-risk. MFS improved with enzalutamide + leuprolide (HR 0.37, 95% CI 0.25‒0.57) and enzalutamide monotherapy (HR 0.57, 95% CI 0.39‒0.83) versus leuprolide alone. MFS and safety for enzalutamide ± leuprolide versus leuprolide alone were similar in EMBARK patients with EAU-consistent or protocol-defined high-risk BCR. Clinical trial registration number: NCT02319837.