Oncology Drug Reference Sheet: Radium 223 Dichloride
Radium 223 dichloride (Xofigo®) is an alpha particle-emitting radioactive therapeutic agent (https://hcp.xofigo-us.com/prescribe-xofigo/overview/) approved by the U.S. Food and Drug Administration in 2013 for castrate-resistant prostate cancer.
Castrate-resistant prostate cancer with symptomatic bone metastases and no known visceral metastatic disease
Administer 55 Kbq (1.49 microcurie) per kg body weight, every four weeks, for six doses.
Give as a slow IV injection over one minute.
More than 10% of patients experience nausea, vomiting, diarrhea, peripheral edema, anemia, lymphocytopenia, leukopenia, thrombocytopenia, and neutropenia. Fewer than 10% experience dehydration (secondary to nausea, vomiting, and diarrhea) and injection site reactions.
The volume administered depends on patient body weight, radioactivity concentration of the product at the reference date, and decay correction factor. No current data are available on the effects of radium 223 dichloride on fertility, but it has the potential for risk. Risk of embryo-fetal toxicity also exists and men should use condoms. Hematologic lab values should be assessed at baseline and prior to every dose.
Prior to the initial dose, lab values should be:
- Absolute neutrophil count: ≥ 1.5 x 109/l
- Platelet count: ≥ 100 x 109/l
- Hemoglobin: ≥ 10g/dl
Prior to subsequent doses, lab values should be:
- Absolute neutrophil count: ≥ 1 x 109/l
- Platelet count: ≥ 50 x 109/l
Discontinue treatment if hematologic lab values do not recover in six to eight weeks after the most recent dose, despite receiving supportive care.
Drug-Drug and Drug-Food Interactions:
Radium 223 is not recommended in combination with abiraterone plus prednisone/prednisolone because of increased risk for fractures and mortality.
Emphasize the importance of blood cell count monitoring, and instruct patients to report signs of bleeding or infection. Encourage adequate hydration, and educate on signs of dehydration and renal insufficiency or failure. Instruct on good hygiene practices (e.g., handwashing) while receiving the drug and for one week after the last injection to minimize radiation exposure. Bodily fluids pose the biggest risk for exposure to radiation; patients should use a toilet whenever possible and flush multiple times after use. Clothing soiled with fecal matter or urine should be laundered promptly and separately from other clothing. Caregivers should use universal precautions for contact with bodily fluids. Patients who are sexually active should use condoms; female partners of reproductive potential should use a highly effective birth control method during and for six month following completion of treatment.
No dosage adjustment is necessary for older adults, and the clinical trial did not report differences in safety or efficacy between older and younger subjects.
Radium 223 dichloride contains a radioactive element and requires radiation safe-handling practices to prevent exposure and possible contamination. Observe radiation precautions in accordance with national and local regulations. If a spill occurs, contact the local radiation safety officer immediately. In the case of contact with skin or eyes, flush the area immediately with water.
Patient Assistance Program
A program is available for uninsured and underinsured patients. Visit xofigoaccessonline.com (https://www.xofigoaccessonline.com/) or call 855-696-3446.