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Risk of development of visceral metastases subsequent to abiraterone vs placebo: An analysis of mode of radiographic progression in COU‐AA‐302
Author(s) -
Teply Benjamin A.,
Qiu Fang,
Antonarakis Emmanuel S.,
Carducci Michael A.,
Denmeade Samuel R.
Publication year - 2019
Publication title -
the prostate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.295
H-Index - 123
eISSN - 1097-0045
pISSN - 0270-4137
DOI - 10.1002/pros.23798
Subject(s) - medicine , prednisone , placebo , prostate cancer , proportional hazards model , oncology , post hoc analysis , abiraterone acetate , clinical endpoint , cancer , abiraterone , gastroenterology , randomized controlled trial , pathology , androgen deprivation therapy , androgen receptor , alternative medicine
Background Abiraterone increases survival in prostate cancer, but tumors resistant to abiraterone can exhibit a hormonally resistant, aggressive phenotype. We hypothesized that the therapeutic pressure of abiraterone is resulting in more clinically aggressive disease at progression, characterized by increased visceral metastases. Our objective was to determine whether abiraterone increased the risk of development of visceral metastases at the time of progression compared with placebo in a randomized phase III trial. Methods We performed a post hoc analysis of the COU‐AA‐302 trial of abiraterone plus prednisone vs placebo plus prednisone in patients with metastatic castration‐resistant prostate cancer. The primary outcome was the development of visceral metastases. The cumulative incidences of visceral metastases were calculated by the Kaplan‐Meier method and compared using log‐rank testing. Multivariable Cox regression analysis assessed for the independent association of abiraterone with the development of visceral metastases. Results Eighty‐four of 1088 patients developed visceral metastases during study. Log‐rank testing and Cox regression showed no difference in time to visceral metastases between groups (HR 1.01 [95% confidence interval (CI), 0.65‐1.56]; P = .97). Abiraterone treatment was not associated with the development of visceral metastases in multivariable analysis (HR 0.89 [95% CI, 0.57‐1.40]; P = .62). The study was limited by censoring of radiographic outcomes at the time of completion of primary study therapy; longer term risks were not assessed. Conclusions Abiraterone was not associated with increased risk of visceral metastatic disease at the time of progression compared with placebo.