Enzalutamide better than bicalutamide for metastatic castration-resistant prostate cancer
Enzalutamide, compared with bicalutamide, is effective in improving clinical outcomes regardless of age in chemotherapy-naïve men with metastatic castration-resistant prostate cancer, reports a recent study.
Treatment with enzalutamide vs bicalutamide significantly lowered the risk of disease progression or death in patients <75 years (hazard ratio [HR], 0.38; 95 percent CI, 0.27‒0.52; p<0.0001) and ≥75 years (HR, 0.59; 0.37‒0.92; p=0.018). In each subgroup, enzalutamide also significantly prolonged time to prostate-specific antigen progression compared with bicalutamide.
Each subgroup had similar adverse event distribution between treatments. However, there were more (5 percent or greater difference between subgroups) atrial fibrillation, urinary tract infections, falls, and decreased appetite, as well as less extremity pain and hot flushing in enzalutamide-treated patients ≥75 years, and less back pain and hot flushing in bicalutamide-treated patients ≥75 years.
Cardiac events with ≥grade 3 were more prevalent in patients ≥75 years vs <75 years in both treatment groups. Fatigue was more common in the enzalutamide group with a similar distribution in each age subgroup.
“Increased falls and cardiac events suggest caution when prescribing to older patients with significant comorbidity,” researchers said.
In this study, men were randomly assigned 1:1 to either enzalutamide 160 mg/day or bicalutamide 50 mg/day. Posthoc analysis was performed on progression-free survival, time to prostate-specific antigen progression, and safety in younger (<75 years) and older (≥75 years) subgroups.
In the TERRAIN trial, enzalutamide significantly prolonged median progression-free survival vs bicalutamide in chemotherapy-naïve men with metastatic castration-resistant prostate cancer, according to researchers.