Novel androgen receptor inhibitors in nonmetastatic castration-resistant prostate cancer: A network meta-analysis.

Abstract

131 Background: Novel non-steroidal anti-androgens (NSAAs) including enzalutamide, apalutamide, and darolutamide with androgen deprivation therapy (ADT) have proven efficacy in men with high-risk non-metastatic castrate resistant prostate cancer (nmCRPC). However, in the absence of direct comparative trials, there is little evidence to guide therapeutic choice. Our objective was to perform a network meta-analysis to compare agents and perform a class-level meta-analysis of NSAAs with androgen deprivation therapy (ADT) versus ADT-alone. Methods: We performed a systematic review of phase III parallel-group RCTs in men ≥18 years of age with nmCRPC using EMBASE and MEDLINE, indexed as of March 8, 2019. Our primary outcome was metastasis free survival (MFS). Secondary outcomes included OS, PSA progression free survival (PFS), and rates of grade 3-4 adverse events (AEs). Three RCTs were identified. We performed a random effects meta-analysis of NSAA versus ADT-alone using the inverse variance technique for meta-analysis for efficacy outcomes and the Mantel-Haenszel method for meta-analysis of dichotomous data for AEs. We then performed a network meta-analysis to compare outcomes between NSAAs using fixed-effect models in a Bayesian framework. We estimated the relative ranking of the different treatments for each outcome. Results: Pooled MFS, PSA-PFS, and OS were significantly greater with NSAA versus placebo (HR:0.32,95%CI:0.25-0.41, HR:0.08,95%CI:0.05-0.13, and HR:0.74,95%CI:0.61-0.90, respectively). Apalutamide and enzalutamide had a 56% and 44% likelihood of maximizing MFS, respectively. There was a 44%, 41%, and 15% likelihood that apalutamide, darolutamide and enzalutamide offered the greatest OS benefit, respectively. There was a 61% chance that darolutamide was preferred with respect to AEs. Conclusions: NSAAs improve survival outcomes in patients with high-risk nmCRPC. Apalutamide and enzalutamide may offer improved oncological outcomes. Darolutamide may result in fewer adverse events. These differences, if confirmed, would be meaningful to patients and practitioners when selecting treatment.