Subanalysis of the PREVAIL Trial: Impact of Enzalutamide on Skeletal-Related Events and Patients’ Quality of Life
PREVAIL was a phase 3, double-blind clinical trial that showed that enzalutamide (an oral androgen receptor inhibitor), when used as first-line therapy in men with metastatic castrate-resistant prostate cancer (mCRPC), significantly decreased the risk for radiographic disease progression and death and delayed the initiation of chemotherapy (Beer TM, et al. N Engl J Med. 2014;371:424-433). PREVAIL also prospectively evaluated skeletal-related events (SREs), pain, and quality-of-life (QOL) measures, as presented by Loriot and colleagues at ESMO 2014 (Loriot Y, et al. ESMO 2014: Abstract 762PD).
In the PREVAIL trial, 1717 patients with mCRPC were randomized to receive enzalutamide 160 mg daily or placebo. SREs were assessed throughout the study, and QOL was assessed at baseline and during the treatment period, using the FACT-P scores for patients with prostate cancer and the visual analog scale. Pain was assessed using the Brief Pain Inventory-Short Form scale at baseline and at 3 and 6 months. Overall, 32% of enzalutamide-treated patients and 37% of placebo-treated patients reported at least 1 SRE; the results showed that enzalutamide significantly reduced the risk for a first SRE (P <.0001).
As shown in the Table, compared with placebo, enzalutamide significantly reduced the risk for deterioration of QOL, as measured by FACT-P scores and subscores, and significantly lowered the proportion of patients with progressive pain during the first 6 months of treatment.