Coprimary end points were radiographic progression-free survival and overall survival. Secondary end points included the time until the initiation of cytotoxic chemotherapy, the time until the first skeletal-related event, the best overall soft-tissue response, the time until PSA progression, and a decline in the PSA level of 50% or more from baseline. Prespecified exploratory end points included quality of life, as measured with the use of the Functional Assessment of Cancer Therapy–Prostate (FACT-P) scale, and a decline in the PSA level of 90% or more from baseline. End-point definitions are provided in Table S1 in the Supplementary Appendix , available at NEJM.org .
Radiographic disease was evaluated with the use of either computed tomography or magnetic resonance imaging and with the use of bone scanning. Imaging was performed at the time of screening, at weeks 9, 17, and 25, and every 12 weeks thereafter. Radiologists at a central location who were unaware of the study-group assignments determined whether there was progressive disease on the basis of Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, for soft tissue or on the basis of criteria adapted from the Prostate Cancer Clinical Trials Working Group 217 (link) for osseous disease (Table S1 in the Supplementary Appendix ).
Radiographic disease was evaluated with the use of either computed tomography or magnetic resonance imaging and with the use of bone scanning. Imaging was performed at the time of screening, at weeks 9, 17, and 25, and every 12 weeks thereafter. Radiologists at a central location who were unaware of the study-group assignments determined whether there was progressive disease on the basis of Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, for soft tissue or on the basis of criteria adapted from the Prostate Cancer Clinical Trials Working Group 217 (link) for osseous disease (