Phase IB Trial of Radium-223 and Niraparib in Patients With Castrate Resistant Prostate Cancer (NiraRad)

This phase Ib trial studies the side effects and best dose of niraparib when given together with radium Ra223 dichloride in treating subjects with prostate cancer that keeps growing even when the amount of testosterone in the body is reduced to very low levels and has spread from the primary site to the bone. Radium Ra 223 dichloride, acts like calcium to target cancer in the bones and may deliver radiation directly to the bone tumors, limiting damage to the surrounding normal tissue. Niraparib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving radium Ra 223 dichloride and niraparib may work better in treating subjects with hormone-resistant prostate cancer metastatic to the bone.