Last reviewed 2026-05-13 · How we verify

Radium-223 (radium-223)

Radium-223, developed by Pfizer Inc., is an alpha-emitting isotope used to treat Castration-Resistant Prostate Cancer with Bone Metastases. It mimics calcium and forms complexes with hydroxyapatite at areas of increased bone turnover. This radiopharmaceutical takes advantage of its chemical similarity to calcium. Radium-223 has shown clinical differentiation in treating metastatic cancers in bone. Its commercial significance lies in its ability to target cancer cells in bone. There are no notable pipeline developments for Radium-223.

At a glance

Approved indications

• Castration-Resistant Prostate Cancer, Bone Metastases

Common side effects

• Anemia
• Nausea
• Lymphocytopenia
• Diarrhea
• Leukopenia
• Vomiting
• Thrombocytopenia
• Neutropenia
• Peripheral edema
• Renal failure and impairment
• Pancytopenia

Serious adverse events

• Lymphocytopenia (Grade 3-4)
• Anemia (Grade 3-4)
• Thrombocytopenia (Grade 3-4)
• Leukopenia (Grade 3-4)
• Neutropenia (Grade 3-4)
• Nausea (Grade 3-4)
• Diarrhea (Grade 3-4)
• Vomiting (Grade 3-4)
• Peripheral edema (Grade 3-4)
• Renal failure and impairment (Grade 3-4)

Drug interactions

• Warfarin
• Aspirin
• Other anticoagulants
• Cyclosporine
• Lithium
• Other nephrotoxic agents
• Furosemide
• Other loop diuretics
• Calcium supplements

Key clinical trials

• Testing the Addition of Radium Therapy (Radium-223 Dichloride) to the Usual Chemotherapy Treatment (Paclitaxel) for Advanced Breast Cancer That Has Spread to the Bones (PHASE2)
• Radiation Medication (Radium-223 Dichloride) Versus Radium-223 Dichloride Plus Radiation Enhancing Medication (M3814) Versus Radium-223 Dichloride Plus M3814 Plus Avelumab (a Type of Immunotherapy) for Advanced Prostate Cancer Not Responsive to Hormonal Therapy (PHASE1, PHASE2)
• Testing the Addition of a New Anti-cancer Drug, Radium-223 Dichloride, to the Usual Treatment (Cabozantinib) for Advanced Renal Cell Cancer That Has Spread to the Bone, RadiCaL Study (PHASE2)
• A Real-world Study of Characteristics, Treatment Patterns, and Clinical Outcomes Among Lutetium-177 Vipivotide Tetraxetan Treated Patients
• Radium-223 in Biochemically Recurrent Prostate Cancer (PHASE2)
• Study of Nivolumab in Combination w Radium-223 in Men w Metastatic Castration Resistant Prostate Cancer (PHASE1)
• RADIANT: A Study of Radium-223 Dichloride (Xofigo) vs Enzalutamide or Abiraterone (ARPIs, Androgen Receptor Pathway Inhibitors) in Patients With Prostate Cancer That Has Spread to the Bones (mCRPC, Metastatic Castration-Resistant Prostate Cancer) (PHASE4)
• A Study to Test Radium-223 With Docetaxel in Patients With Prostate Cancer (PHASE3)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Radium-223 CI brief — competitive landscape report
• Radium-223 updates RSS · CI watch RSS
• Pfizer portfolio CI