Radium-223 chloride: extending life in prostate cancer patients by treating bone metastases
Mené sur 923 patients atteints d'un cancer métastatique de la prostate résistant à la castration, cet essai de phase III évalue l'intérêt du radium 223 pour traiter des métastases osseuses et prolonger la survie des patients
The treatment scope for patients with metastatic castrate-resistant prostate cancer (mCRPC) is rapidly expanding. On May 15, 2013, the FDA approved radium-223 chloride for the treatment of mCRPC patients whose metastases are limited to the bones. Radium-223 is an alpha-emitting alkaline earth metal ion, which, similar to calcium-ions, accumulates in the bone. In a phase 3 study (ALSYMPCA), mCRPC patients with bone metastases received best standard-of-care with placebo or radium-223 chloride. At a prespecified interim analysis, the primary endpoint of median overall survival was significantly extended by 3.6 months in patients treated with radium-223 compared to placebo (p < 0.001). The radioisotope was well tolerated and gave limited bone marrow suppression. Radium-223 chloride is the first bone targeting antitumor therapy which received FDA approval based on a significant extended median overall survival. Further studies are required to optimize its dosing and to confirm its efficacy and safety in cancer patients.