Purpose Orteronel (TAK-700) is an investigational, nonsteroidal, reversible, selective 17,20-lyase inhibitor. This study examined orteronel in patients with metastatic castration-resistant prostate cancer that progressed after docetaxel therapy. Patients and Methods In our study, 1,099 men were randomly assigned in a 2:1 schedule to receive orteronel 400 mg plus prednisone 5 mg twice daily or placebo plus prednisone 5 mg twice daily, stratified by region (Europe, North America [NA], and non-Europe/NA) and Brief Pain Inventory–Short Form worst pain score. Primary end point was overall survival (OS). Key secondary end points (radiographic progression-free survival [rPFS], ≥ 50% decrease of prostate-specific antigen [PSA50], and pain response at 12 weeks) were to undergo statistical testing only if the primary end point analysis was significant. Results The study was unblinded after crossing a prespecified OS futility boundary. The median OS was 17.0 months versus 15.2 months with orteronel-prednisone versus placebo-prednisone (hazard ratio [HR], 0.886; 95% CI, 0.739 to 1.062; P = .190). Improved rPFS was observed with orteronel-prednisone (median, 8.3 v 5.7 months; HR, 0.760; 95% CI, 0.653 to 0.885; P < .001). Orteronel-prednisone showed advantages over placebo-prednisone in PSA50 rate (25% v 10%, P < .001) and time to PSA progression (median, 5.5 v 2.9 months, P < .001) but not pain response rate (12% v 9%; P = .128). Adverse events (all grades) were generally more frequent with orteronel-prednisone, including nausea (42% v 26%), vomiting (36% v 17%), fatigue (29% v 23%), and increased amylase (14% v 2%). Conclusion Our study did not meet the primary end point of OS. Longer rPFS and a higher PSA50 rate with orteronel-prednisone indicate antitumor activity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.