General Information

Xofigo (radium Ra 223 dichloride), an alpha particle-emitting pharmaceutical, is a radiotherapeutic drug.

Xofigo is specifically indicated for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases and no known visceral metastatic disease.

Xofigo is supplied as a solution for intravenous administration. The recommended dose is s 50 kBq (1.35 microcurie) per kg body weight, given at 4 week intervals for 6 injections.

Clinical Results

FDA Approval
The FDA approval of Xofigo was based on a double-blind, randomized, placebo-controlled phase III clinical trial of 809 subjects with castration-resistant prostate cancer with symptomatic bone metastases. Subjects with visceral metastases and malignant lymphadenopathy exceeding 3 cm were excluded. The subjects received Xofigo 50 kBq (1.35 microcurie)/kg intravenously every 4 weeks for 6 cycles plus best standard of care or matching placebo plus best standard of care. The primary efficacy endpoint was overall survival. The pre-specified interim analysis of overall survival revealed a statistically significant improvement in patients receiving Xofigoplus best standard of care compared with patients receiving placebo plus best standard of care. An exploratory updated overall survival analysis performed before patient crossover with an additional 214 events resulted in findings consistent with the interim analysis. At the interim analysis the median survival was 14 months versus 11.2 months, respectively. At the updated analysis the median survival was 14.9 versus 11.3 months, respectively.

Side Effects

Adverse events associated with the use of Xofigo may include, but are not limited to, the following:

• nausea
• diarrhea
• vomiting
• peripheral edema

Mechanism of Action

Xofigo (radium Ra 223 dichloride), an alpha particle-emitting pharmaceutical, is a radiotherapeutic drug. 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 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 which limits damage to the surrounding normal tissue.

Additional Information

For additional information regarding Xofigo or prostate cancer and bone metastases, please visit the Bayer web page.