ASCO Genitourinary Cancers Symposium (Zytiga & radiation in highish-risk local PCa.)

[pjoshea13]

"Eligibility included 2+ intermediate or 1 high NCCN risk factors and no metastatic disease. Men received 6 months of ADT concurrently with 1000mg AA/5mg P {abiraterone acetate plus prednisone} daily and 78 Gy RT to prostate/SV. Primary endpoint was PSA , 0.1 ng/ml at 1 year."

"In men with high risk intermediate or limited high risk PC, utilizing short-term ADT/AAP with definitive RT shows 1) high rate of testosterone recovery and good quality of life and 2) excellent PSA control at 1 and 2 years."

-Patrick

11 Poster Session (Board #A17), Thu, 11:30 AM-1:00 PM and

5:15 PM-6:15 PM

Phase II trial of 6 months ADT/abiraterone acetate plus prednisone (AAP) and definitive radiotherapy (AbiRT) for men with intermediate to high risk localized prostate cancer.

Bridget F. Koontz, Karen E. Hoffman, Patrick Healy, Daniel J. George, Michael Roger Harrison, Tian Zhang, W. Robert Lee, William R. Berry, Thomas J Pugh, Paul Gettys Corn, LuEllen Bratt, Kellie Shobe, Blair Thornburg, Donna M. Allen, Katie Brummer, Beth Tojong, Bridget Hobbs, Susan Halabi, Andrew J. Armstrong; Duke University Medical Center, Durham, NC; UT MD Anderson Cancer Center, Houston, TX; Duke Cancer Institute, Duke University, Durham, NC; Duke Cancer Institute, Duke University Medical Center, Durham, NC; Duke University School of Medicine, Durham, NC; Duke University School of Medicine, Raleigh, NC; University of Colorado, Aurora, CO; Duke Cancer Center, Raleigh, NC; Duke Cancer Institute, Duke University, Raleigh, NC

Background: Combined external beam radiotherapy (RT) and androgen deprivation therapy (ADT) improves survival over RT alone for high risk prostate cancer (PC). Long-term ADT use, currently recommended for high risk PC, also increases toxicity. Recent data suggests synergistic efficacy with the addition of abiraterone acetate plus prednisone (AAP) to RT/ADT. Potent androgen blockade may provide biochemical control with short-term ADT course in men with aggressive but localized PC.

Methods: This was a two center prospective phase 2 single arm clinical trial within the Department of Defense PCCTC (NCT01717053). Eligibility included 2+ intermediate or 1 high NCCN risk factors and no metastatic disease. Men received 6 months of ADT concurrently with 1000mg AA/5mg P daily and 78 Gy RT to prostate/SV. Primary endpoint was PSA , 0.1 ng/ml at 1 year. Secondary objectives included BPFS, PSA nadir, testosterone recovery, toxicity, and patient- reported QOL.

Results: We enrolled 37 men (82% white, 18% black) with intermediate to high risk localized PC; 33 completed course of treatment (4 patients halted early for personal preference (N = 2), planned prostatectomy, or renal artery stenosis). Median age was 66 years; 46% Gleason 8-10, 40% Gleason 4+3 = 7, 62% T1c. Median follow-up is 23 months. Regimen was well tolerated with 12 (32%) G3 toxicities (10 hypertension, 2 hyperglycemia, 1 hypokalemia); no G4-5 or unexpected toxicities were observed. At 12 months from enrollment, PSA remained at undetectable levels in 52% of men. Testosterone recovery to normal lab value occurred in 12 (62%) at 12 months. In those patients, 20 (95%) and 21 (100%) remained with PSA under 0.5 and 1.0 ng/ml, respectively. No patient has failed by Phoenix definition to date. 1 year EPIC QOL had median summary scores above 90 for incontinence, urinary, bowel, hormonal, and satisfaction. Sexual summary score fell from median of 46 at baseline to 26 at 1 year.

Conclusions: In men with high risk intermediate or limited high risk PC, utilizing short-term ADT/AAP with definitive RT shows 1) high rate of testosterone recovery and good quality of life and 2) excellent PSA control at 1 and 2 years. Clinical trial information: NCT01717053.