Enzalutamide Improves Patient-Reported Outcomes and Time to Skeletal-Related Event vs Placebo in PREVAIL Trial
The PREVAIL trial showed that enzalutamide (Xtandi) improved overall survival and progression-free survival vs placebo in asymptomatic/minimally symptomatic chemotherapy-naive patients with metastatic castration-resistant prostate cancer. In analyses reported in The Lancet Oncology, Loriot et al found that enzalutamide treatment was associated with improved patient-reported outcomes and an increased time to first skeletal-related event in the trial.
Study Details
In the double-blind trial, patients were randomly assigned to receive enzalutamide 160 mg/d (n = 872) or placebo (n = 845). Health-related quality of life was assessed at baseline and during treatment using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) and EuroQol-5 dimension (EQ-5D) questionnaires. Pain status was assessed at screening, baseline, week 13, and week 25 with the Brief Pain Inventory Short Form (BPI-SF).
Quality of Life
Significant between-treatment differences in change from baseline to week 61 for enzalutamide vs placebo were observed for most FACT-P endpoints and the EQ-5D visual analog scale. Median time to deterioration in FACT-P total score was 11.3 months vs 5.6 months (hazard ratio [HR] = 0.62, P < .0001). Clinically meaningful improvements were observed for the FACT-P total score in 40% vs 23%, for the EQ-5D utility index in 28% vs 16%, and for the EQ-5D visual analog scale in 27% vs 18% (P < .0001 for all comparisons).
Pain
Median time to progression to worst pain was 5.7 months vs 5.6 months (HR = 0.62, P < .0001). Progression to pain at its worst was significantly less common in the enzalutamide group at week 13 (29% vs 42%, P < .0001) but not at week 25 (32% vs 38%, P = .068).
Time to Skeletal-Related Event
At the time of analysis, a first skeletal-related event had occurred in 32% of the enzalutamide group vs 37% of the placebo group. Median time to first skeletal-related event was 31.1 months (95% confidence interval [CI] = 29.5 months to not reached) vs 31.3 months (95% CI = 23.9 months to not reached; HR = 0.72, P < .0001).
The investigators concluded: “In addition to improving overall survival relative to placebo, enzalutamide significantly improves patient-related outcomes and delays occurrence of first skeletal-related event in chemotherapy-naive men with metastatic castration-resistant prostate cancer.”
Yohann Loriot, MD, of Institut Gustave Roussy, University of Paris Sud, is the corresponding author of The Lancet Oncology article.
The study was funded by Astellas Pharma and Medivation. For full disclosures of the study authors, visit www.thelancet.com.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
