radium-223 dichloride + bisphosphonate

Radium-223 dichloride + bisphosphonate is a combination therapy 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, selectively localizing in areas of increased bone turnover, particularly at bone metastases, and inducing double-strand DNA breaks in adjacent cells, leading to anti-tumor and bone-modifying effects. **Bisphosphonates** are antiresorptive agents that inhibit osteoclast-mediated bone resorption and are standard supportive care for reducing skeletal-related events in metastatic cancers. Clinical evidence shows added benefit and survival advantage for this combination, particularly in patients under 65 years old or patients over 65 years old on bisphosphonate therapy. This regimen is most widely used for patients for whom chemotherapy is not indicated, and is not recommended with cytotoxic chemotherapy due to increased risk of myelosuppression[2][3]. Approximately 40% of patients in key registration trials received concurrent bisphosphonate therapy alongside radium-223, resulting in delayed onset of bone symptoms and improved survival outcomes[2].