FDA approves Xofigo for metastatic prostate cancer

The FDA today approved radium Ra 223 dichloride as a treatment for men with metastatic castration-resistant prostate cancer.

Radium Ra 223 dichloride (Xofigo, Bayer) is intended for men whose disease spread to bones but not to other organs after medical or surgical therapy to lower testosterone, according to an FDA press release.

The drug was approved under the agency’s priority review program, which allows expedited review of drugs with the potential to significantly improve existing treatments or offer an effective therapy when no satisfactory alternative exists.

Richard Pazdur

“Xofigo binds with minerals in the bone to deliver radiation directly to bone tumors, limiting the damage to the surrounding normal tissues,” Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said in the press release.

The FDA based its approval in part on results of a trial that involved 809 men with castration-resistant prostate cancer. The patients, all of whom had bone metastases, were randomly assigned to receive standard care plus either radium Ra 223 or placebo.

OS served as the primary endpoint.

Median OS was 14 months among patients assigned to the study drug compared with 11.2 months for patients who received placebo, according to results of a pre-planned interim analysis. An exploratory updated analysis later confirmed the drug’s ability to extend OS, according to the FDA.

The most common adverse effects experienced by patients assigned to the study drug were nausea, diarrhea, vomiting and swelling of the leg, ankle or foot. The most common abnormalities detected during blood testing included anemia, lymphocytopenia, leukopenia, thrombocytopenia and neutropenia.