HealthDay News — Enzalutamide treatment can significantly lower risk of metastasis or death in men with rapidly advancing, castration-resistant prostate cancer, according to a phase 3 study published online June 28 in the New England Journal of Medicine.
Maha Hussain, MD, from Northwestern University in Chicago, and colleagues randomly assigned (2 to 1) 1,401 men with nonmetastatic, castration-resistant prostate cancer (median PSA doubling time, 3.7 months) to receive enzalutamide (at a dose of 160mg) or placebo once daily plus continuation of androgen-deprivation therapy.
The researchers found that a total of 219 of 933 patients (23%) in the enzalutamide group had metastasis or had died vs 228 of 468 (49%) in the placebo group. In the enzalutamide group, the median metastasis-free survival was 36.6 months vs 14.7 months in the placebo group (hazard ratio [HR] for metastasis or death, 0.29; P<0.001). Compared with placebo, the time to the first use of a subsequent antineoplastic therapy was longer with enzalutamide treatment (HR, 0.21; P<.001) as was the time to prostate specific antigen progression (HR, 0.07; P<.001). Adverse events (≥grade 3) occurred in 31% of the enzalutamide group and in 23% of the placebo group.
“Among men with nonmetastatic, castration-resistant prostate cancer with a rapidly rising PSA level, enzalutamide treatment led to a clinically meaningful and significant 71% lower risk of metastasis or death than placebo,” conclude the authors.
Several authors report financial ties to the pharmaceutical industry, including Pfizer and Astellas Pharma, which funded the study.