Medication Pearl of the Day: Xofigo (Radium Ra 223 Dichloride)
Indication: Xofigo is an alpha particle-emitting radioactive therapeutic agent indicated for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases, and no known visceral metastatic disease. Xofigo treats cancer that no longer responds to hormonal or surgical treatment to reduce testosterone. It is indicated for men whose prostate cancer has spread to the bone with symptoms but not to other parts of the body.
Insight:
- Dosing: The dose regimen of Xofigo is 50 kBq (1.35 microcurie) per kg body weight, administered at 4-week intervals for 6 injections.
- Dosage forms: Single-use vial at a concentration of 1000 kBq/mL (27 microcurie/mL) at the reference date with a total radioactivity of 6000 kBq/vial (162 microcurie/vial) at the reference date.
- Adverse events: The most common adverse drug reactions (≥ 10%) in patients receiving Xofigo were nausea, diarrhea, vomiting, and peripheral edema.
- Mechanism of action: The active moiety of Xofigo is the alpha particle-emitting isotope radium-223 (as radium Ra 223 dichloride), which mimics calcium and forms complexes with the bone mineral hydroxyapatite at areas of increased bone turnover, such as bone metastases. The high linear energy transfer of alpha emitters (80 keV/micrometer) leads to a high frequency of double-strand DNA breaks in adjacent cells, resulting in an anti-tumor effect on bone metastases. The alpha particle range from radium-223 dichloride is less than 100 micrometers (less than 10 cell diameters) which limits damage to the surrounding normal tissue.
- Manufacturer: Bayer Healthcare
Source:
Xofigo (radium Ra 223 dichloride) Injection (fda.gov)