ATLANTA—Enzalutamide, an investigational oral medication formerly known as MDV3100, prolongs survival by nearly five months in men with late-stage prostate cancer previously treated with docetaxel, according to data presented at the American Urological Association 2012 annual meeting.

The data are from a multinational phase 3 trial in which 1,199 patients were randomly assigned to receive either 160 mg/day of enzalutamide (800 patients)—a once-daily oral androgen receptor signaling inhibitor—or placebo (399 patients).

Based on a planned interim analysis at 520 death events, an Independent Data Monitoring Committee recommended that the study be unblinded and eligible placebo recipients offered enzalutamide due to a significant 4.8 month median overall survival benefit compared with placebo (median 18.4 vs. 13.6 months). Enzalutamide treatment was associated with a 37% decreased risk of death relative to placebo, lead investigator Neal Shore, MD, of Carolina Urologic Research Center in Myrtle Beach, S.C., told colleagues.

The most frequently reported adverse event occurring more with enzalutamide than placebo was fatigue (34% vs. 29%).

The survival benefit observed with enzalutamide is larger than that seen with abiraterone (median 3.9 months) and cabazitaxel (median 2.4 months).