In men with a rising PSA following radical prostatectomy, salvage radiation therapy (SRT) offers a second chance for cure. Hormonal therapy can be combined with SRT in order to increase prostate tumor control, albeit with associated higher rates of treatment side effects. This trial studies the effectiveness of SRT combined with hormonal therapy using a more potent anti-androgen with a favorable side effect profile. Enzalutamide, a next generation selective androgen receptor antagonist, is approved by the Food and Drug Administration for the treatment of metastatic castrate-resistant prostate cancer (CRPC) where it has been shown to improve overall survival in combination with androgen deprivation therapy. The primary objective of this study is to evaluate the efficacy of combination SRT and enzalutamide for freedom-from-PSA-progression. Secondary objectives include time to local recurrence within the radiation field, metastasis-free survival and safety as determined by frequency and severity of adverse events.

This is a randomized, double-blind, phase II, prospective, multicenter study in adult males with biochemically recurrent prostate cancer following radical prostatectomy. Following registration, enzalutamide 160 mg or placebo by mouth (PO) once daily will be administered for 6 months. Following two months of study drug, external beam radiotherapy to 66.6-70.2 Gray (Gy) will be administered to the prostate bed over 7-8 weeks while continuing daily placebo/enzalutamide. This is followed by two additional months of placebo/enzalutamide.

The SALV-ENZA trial is the first phase II placebo-controlled double-blinded randomized study to test SRT in combination with a next generation androgen receptor antagonist in men with high-risk recurrent prostate cancer after radical prostatectomy. The primary hypothesis of this study is that clinical outcomes will be improved by the addition of enzalutamide compared to standard-of-care SRT alone and pave the path for phase III evaluation of this combination.

ClinicaltTrials.gov Identifier: NCT02203695 Date of Registration: 06/16/2014. Date of First Participant Enrollment: 04/16/2015.

BMC cancer. 2019 Jun 13*** epublish ***

Roche Kapoor, Matthew P Deek, Riley McIntyre, Natasha Raman, Megan Kummerlowe, Iyah Chen, Matt Gaver, Hao Wang, Sam Denmeade, Tamara Lotan, Channing Paller, Mark Markowski, Michael Carducci, Mario Eisenberger, Tomasz M Beer, Daniel Y Song, Theodore L DeWeese, Jason W Hearn, Stephen Greco, Curtiland DeVille, Neil B Desai, Elisabeth I Heath, Stanley Liauw, Daniel E Spratt, Arthur Y Hung, Emmanuel S Antonarakis, Phuoc T Tran

Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 1550 Orleans Street, CRB2 Rm 406, Baltimore, MD, 21231, USA., Department of Medical Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 1650 Orleans Street, CRB1 Rm 1M45, Baltimore, MD, 21231, USA., Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA., OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA., Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, USA., Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA., Karmanos Cancer Institute, Department of Oncology, Wayne State University School of Medicine, Detroit, MI, USA., Department of Radiation Oncology and Cellular Oncology, University of Chicago, Chicago, IL, USA., Department of Radiation Medicine, OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA., Department of Medical Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 1650 Orleans Street, CRB1 Rm 1M45, Baltimore, MD, 21231, USA. ., Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, 1550 Orleans Street, CRB2 Rm 406, Baltimore, MD, 21231, USA. .

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