On July 29, 2018, we published a post, Xofigo (Radium-223)- Cautionary Information where we urged men to be very cautious and talk to their doctors before using Xofigo (Radium-223) in combination with Zytiga. We also indicated that we were concerned about using Radium in combination with any of the other second-line hormone agents. Our concern came from evidence that men taking a combination of Radium and Zytiga were experiencing very high rates of severe fractures.
A presentation about data from two separate studies that were presented at the 2019 ASCO conference demonstrates that if a man is also taking a bone protecting agent like Zoledronic acid or denosumab, the fracture risk we expressed concern about that is associated with Enzalutamide and Zytiga in combination with Ra223 for Prostate Cancer is eliminated.
These findings strongly reinforce the need to be sure that you are following the guidelines regarding bone health monitoring and use of bone-protecting agents when receiving Radium Therapy. Generally, the guidelines say that before using Radium, a man should start one of the bone-strengthening medications at least six weeks before Radium use.
The ERA-223 study (a company-sponsored registration trial) shows that the administration of a bone-protecting agent before initiation of radium-223 dichloride (Radium-223), when used in combination with Zytiga (abiraterone), eliminates the increased risk of fracture among men being treated for metastatic castration-resistant prostate cancer.
Similar results were reported from the EORTC -1333-GUCG/PEACEIII (European Organization for Research and Treatment of Cancer), study for the combination of Radium-223 and Xtandi (enzalutamide).
The ASCO presenter, Dr. Tombal MD, Ph.D., of Cliniques Universitaires Saint Luc and Université Catholique de Louvain in Brussels, Belgium, pointed out that bone protecting agents, “have been registered for years and are recommended by most guidelines.”
He also said, “However, only one-third of patients receive these treatments regularly. (These findings) should reinforce the message that patients should be monitored for bone health at regular intervals. … and (bone protecting agents should be) used earlier in that setting.”
You should note that there still remains a warning on the FDA approved “label” for Zytiga. This data is new and it is possible that Janssen Biotech will request that there be some modification of the warning.
YOUR TAKE HOME
Make sure that you and your doctor use the bone-protecting approved medications (zoledronic acid or denosumab), especially for at least three weeks before using Xofigo (Radium-223).