Xofigo (Radium-223) - Cautionary Information

The European Medicines Agency (EMA) has recommended that the use of Xofigo (Radium-223) be restricted.  The restrictions, because of safety and efficacy concerns in men with castrate resistant prostate cancer (mCRPC), include that Xofigo can be used only after two other treatments have been taken; when other therapies cannot be used and not in combination with other 2nd line hormone therapies. 

After having completed its review of Xofigo (radium-223 dichloride), the European Medicines Agency (EMA) has recommended restricting its use.

The restrictions include that it not be used unless men with mCRPC have had at least two previous treatments or who cannot receive other treatments.

The EMA also has said that Xofigo should not be used with other systemic cancer therapies, (specifically mentioned was Zytiga) except for treatments to maintain reduced levels of male hormones (1stline hormone therapy, ADT). They also stated that Xofigo should also not be used in men who have no symptoms, in line with the current indication; also, the use of Xofigo is not recommended in men with a low number of bone metastases called osteoblastic bone metastases.

The EMA carried out their review of Xofigo after data from a clinical study suggested that men given Xofigo in combination with Zytiga and prednisone could be at risk of dying earlier.  The study found that men who took Zytiga with Xofigo died on average 2.6 months earlier than those given Zytiga with placebo.

The study also found that men taking the combination therapy of Zytiga and Xofigo also suffered more fractures than men given placebo with Zytiga and prednisone.  The study found that 29% of men who received the Xofigo in combination with Zytiga had fractures, compared with 11% of men given the placebo combination.

It is believed that Xofigo, which is taken up by the bone, accumulates at sites where the bone is already damaged, thus increasing the risk of developing additional fractures. The reasons for the decreased survival seen in this study is not understood. 

The EMA’s recommendations will be sent to the European Commission for a final legal decision.

Whether or not you live in a jurisdiction under control of the European Commission you need to take heed of the study results.  Zytiga is an excellent drug, but you should talk to your doctor before you use it, especially if you are also taking Zytiga. It is not clear from this specific study if it is safe to use Xofigo in combination with the other 2nd line hormone therapy Xtandi, despite the EMA’s overall recommended restrictions against the use of all combination 2nd line hormone therapies with Xofigo.  An additional study evaluating the safety of the combination of Xtandi and Xofigo needs to be performed.  

 The Agency’s recommendations are based on the assessment of data from a randomized, double blind, placebo-controlled phase III trial (ERA-223)

Joel T. Nowak, MA, MSW wrote this Post.  Joel is the CEO/Executive Director of Cancer ABCs.  He is a Cancer Thriver diagnosed with five primary cancers - Thyroid, Metastatic Prostate, Renal, Melanoma, and the rare cancer Appendiceal cancer.