Overall Survival Significantly Increased With Radium-223 Chloride in Castration-Resistant Prostate Cancer
Results of the preplanned interim analysis of the ALSYMPCA (Alpharadin in Symptomatic Prostate Cancer) trial were presented in September at the European Multidisciplinary Cancer Congress in Stockholm, Sweden (Abstract 1LBA). The trial was an international, randomized, double-blind, placebo-controlled, phase III study of radium-223 chloride (Alpharadin, Bayer HealthCare Pharmaceuticals) plus best standard of care compared with a placebo plus best standard of care in men with metastatic, castration-resistant prostate cancer (mCRPC). A total of 922 enrolled patients who had either failed prior docetaxel-based chemotherapy or were not eligible to be treated with docetaxel-based chemotherapy received up to 6 intravenous treatments with radium-223 chloride or placebo, with a 4-week period between each treatment. Results of the preplanned interim analysis were strong enough to prematurely stop the trial. The study met its primary endpoint of overall survival; radium-223 improved overall survival by 44% compared to placebo (median of 14 months vs 11.2 months, respectively; HR, 0.695; P=.00185). The time to first skeletal-related event significantly improved from 8.4 months with placebo to 13.6 months with radium-223 (HR, 0.61; P=.00046). Levels of total alkaline phosphatase (ALP) were normalized in 33% of men treated with radium-223 versus 1% of men who received a placebo. Treatment with radium-223 improved time to prostate-specific antigen (PSA) progression by 49% compared to placebo (HR, 0.671; P=.00015). Radium-223 chloride is not yet approved in the United States or Europe, but it was granted fast track designation by the US Food and Drug Administration (FDA) in August 2011.
Clinical Advances 