Wednesday, February 1, 2012 (Last Updated: 02/02/2012)WEDNESDAY, Feb. 1 (HealthDay News) -- Radium-223 chloride (Ra-223) improves overall survival (OS) for men with castration-resistant prostate cancer (CRPC) bone metastases; and MDV3100 improves OS for men with CRPC who have progressed following docetaxel-based chemotherapy, according to two phase III studies presented at the annual American Society of Clinical Oncology's Genitourinary Cancers Symposium, held from Feb. 2 to 4 in San Francisco.
A. Oliver Sartor, M.D., from the Tulane Cancer Center in New Orleans, and colleagues compared Ra-223 plus best standard of care (BSC) with placebo plus BSC for 922 CRPC patients with bone metastases. The investigators found that, at an interim analysis, OS was significantly improved with Ra-223 versus placebo (median OS, 14.0 versus 11.2 months; hazard ratio [HR], 0.695). Skeletal-related events were lower and the time to first skeletal-related event was significantly delayed in the Ra-223 group versus placebo.
Howard I. Scher, M.D., from the Memorial Sloan-Kettering Cancer Center in New York City, and colleagues investigated whether MDV3100 could prolong OS for 1,199 men with CRPC who progressed after docetaxel-based chemotherapy. At an interim analysis at 520 death events the researchers observed a significant OS benefit of MDV3100 (HR, 0.631). As a result, the Independent Data Monitoring Committee recommended unblinding the study, and placebo patients were offered MDV3100. The estimated median OS for MDV3100 versus placebo was 18.4 versus 13.6 months.
"MDV3100, a novel androgen receptor signaling inhibitor, significantly improves OS in men with post-docetaxel treated CRPC, reducing the risk of death by 37 percent relative to placebo," Scher and colleagues write.
Several authors from the Sartor study disclosed financial ties to pharmaceutical companies, including Algeta, which manufactures Ra-223. Several authors from the Scher study disclosed financial ties to pharmaceutical companies, including Medivation, which manufactures MDV3100.
Hematology & Oncology
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