radium-223 dichloride + abiraterone + prednisone + prednisolone

This is a **combination therapy** consisting of radium-223 dichloride, abiraterone, prednisone, and prednisolone, used primarily in the treatment of metastatic castration-resistant prostate cancer (mCRPC) with bone metastases. - **Radium-223 dichloride** is a targeted alpha-emitting radiopharmaceutical that mimics calcium to localize in bone, delivering localized radiation and causing double-strand breaks in tumor cell DNA, leading to cell death. - **Abiraterone** is a small molecule inhibitor of **cytochrome P450 17A1 (CYP17A1)**, an enzyme crucial in androgen biosynthesis, thereby suppressing androgen production that drives prostate cancer progression. - **Prednisone** and **prednisolone** are synthetic glucocorticoid steroids, used to manage side effects from abiraterone (notably, mineralocorticoid excess) and may contribute additional anti-tumor activity via immunosuppression and reduction of inflammation. The combination aims to attack prostate cancer via different mechanisms: engineering DNA damage in metastasized bone lesions (radium-223), inhibiting androgen production (abiraterone), and mitigating side effects or providing symptomatic relief (prednisone/prednisolone). This combination is not a fixed-dose co-formulation but refers to the practice of co-administering these agents. Combination use, especially of radium-223 with abiraterone/prednisone, has shown mixed data for efficacy and safety—some studies report improvements in progression-free survival and quality of life, while others note an increased risk of bone fractures[1][3][5].