Radium-223 Dichloride — Drug Monograph

Brand names: Xofigo

Drug class: Radiopharmaceutical

Mechanism of Action

Alpha-particle-emitting calcium mimetic. Radium-223 behaves like calcium and forms complexes with hydroxyapatite in areas of increased bone turnover, such as osteoblastic bone metastases. The emitted high-energy alpha particles have a very short tissue range (<100 microns), inducing double-strand DNA breaks in adjacent tumor cells while sparing surrounding normal tissue and minimizing marrow toxicity.

FDA Indications

• Castration-resistant prostate cancer with symptomatic bone metastases and no known visceral metastatic disease

Common Side Effects

• Nausea
• Diarrhea
• Vomiting
• Peripheral edema
• Anemia
• Thrombocytopenia
• Fatigue

Clinical Pearl

Radium-223 is the only alpha-emitting radiopharmaceutical shown to improve overall survival in CRPC with symptomatic bone metastases (ALSYMPCA). It is reserved for patients WITHOUT visceral metastases. Do not combine with abiraterone plus prednisone — the ERA-223 trial showed increased fractures and deaths; ensure adequate bone-protective agents.

Related Therapies & Mechanisms

• Lutetium Lu 177 Vipivotide Tetraxetan (Pluvicto) — Radiopharmaceutical · Prostate
• Lutetium Lu 177 dotatate (Lutathera) — Radiopharmaceutical
• Lutetium-177 DOTATATE (Lutathera) — Radiopharmaceutical
• Abiraterone Acetate (Zytiga) — Prostate