Radium 223 for the treatment of metastatic castration-resistant prostate cancer

The treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) has evolved dramatically in the recent years with the approval of several new drugs. Together with other treatment modalities including chemotherapy, hormonal therapy and immunotherapy, radiopharmaceuticals have recently been incorporated to the therapeutic scenario of prostate cancer with the approval of Radium 223 dichloride (Ra-223) for the treatment of mCRPC patients with symptomatic bone metastasis and no visceral metastases. Radiopharmaceuticals have long been used for pain palliation in patients with bone metastases. However, the bone seeking properties and the favourable physical characteristic of alpha emitter radium 223 encouraged the clinical development of the drug, leading to survival advantage in the phase III trial ALSYMPCA. Now the efforts are directed to define the optimal patient selection and drug sequence. In this review, we will provide the best available evidence of mechanism of action, clinical data and future directions of Ra-223 in mCRPC.