Adjuvant Enzalutamide (Enza) For Men With Non-Metastatic High-Risk Prostate Cancer (Hrpca) After Radical Prostatectomy (Rp).

88Background: Management of HRPCa is a clinical challenge. Novel AR inhibitors could potentially impact outcome in HRPCa men following RP. We conducted a phase II study evaluating the efficacy/safety of Enza in men with HRPCa following RP. Methods: HRPCa pts (≥pT3a, GS≥8, iPSA ≥20 ng/mL, +ve lymph nodes (LN), or ≥35% chance of biochemical recurrence (BCR) at 5 yrs based on MSKCC’s nomogram) with undetectable PSA within 3 months from RP were eligible. Enza 160mg PO daily was given in 28-day cycles until disease progression, intolerability, consent withdrawal, or study completion at 24 months. Accrual goal was N=40 to provide 80% power to detect a 75% decrease in the risk of BCR from historical 55% rate. BCR was defined as PSA ≥0.2ng/mL on 2 consecutive lab results or any PSA rise that resulted in subsequent therapy. Results: 42 men enrolled. Median age 59 (range 43-70), based on biopsy 45% were GS7; 36% GS8, 19% GS9. 76% men had cT1, 24% cT2, median iPSA was 8.2 (range 2-77). On prostatectomy pathology: 50...