Radium Ra 223 dichloride (Xofigo; Bayer Pharmaceuticals) was approved by the US Food and Drug Administration (FDA) for men with metastatic, castration-resistant prostate cancer (CRPC) that has spread to bones but not to other organs. Ra 223 dichloride is an alpha particle-emitting radioactive therapy that is used to lower the testosterone levels for patients whose cancer has spread after medical or surgical therapy.
The approval of Ra 223 dichloride was done under the FDA’s priority review program and 3 months ahead of the scheduled FDA review. “Xofigo binds with minerals in the bone to deliver radiation directly to bone tumors, limiting the damage to the surrounding normal tissues,” said Richard Pazdur, MD, Director of the FDA’s Office of Hmatology and Oncology Products. “Xofigo is the second prostate cancer drug approved by the FDA in the past year that demonstrates an ability to extend the survival of men with metastatic prostate cancer.”
The safety and efficacy of Ra 223 dichloride were demonstrated in a single, randomized, placebo-controlled trial of 809 men with symptomatic CRPC that spread to bone but not to other organs. The primary end point was overall survival (OS). Interim results from a preplanned analysis showed that the median OS was 14 months in patients who were randomized to Ra 223 dichloride versus a median of 11.2 months for men receiving placebo plus best standard of care.
The most common side effects with Ra 223 dichloride were nausea, diarrhea, vomiting, and swelling in the lower extremities. The most common hematologic abnormalities included anemia, lymphocytopenia, leukopenia, thrombocytopenia, and neutropenia. (May 15, 2013)
