Results of a Phase II Study of LHRH Therapy in High-Risk Prostate Cancer

Bridget F. Koontz, MD

Bridget F. Koontz, MD, associate professor of radiation oncology, Duke Cancer Institute, discusses a single-arm, phase II trial of 6 months of concurrent androgen deprivation therapy/abiraterone acetate (Zytiga) plus prednisone and definitive radiotherapy for men with intermediate- to high-risk localized prostate cancer.

Bridget F. Koontz, MD, associate professor of radiation oncology, Duke Cancer Institute, discusses a single-arm, phase II trial of 6 months of concurrent androgen deprivation therapy/abiraterone acetate (Zytiga) plus prednisone and definitive radiotherapy for men with intermediate- to high-risk localized prostate cancer.

Koontz says the regimen was well tolerated, with a low grade 3 toxicity rate, mostly related to abiraterone. All 33 patients enrolled on the trial were able to complete therapy. At 1 year, about half of the patients had full testosterone recovery.

Koontz adds that the PSAs were excellent, with very low nadirs, which is important for radiation. There is data that suggests that low PSA nadir with radiation is prognostic for late outcome, she says. In the men who had testosterone recovery, 95% of the patients had PSAs under 0.5.