TAT-11: Real-World Treatment Experience with Xofigo®

Ottawa, ON, Canada (UroToday.com) Dr. Dan George concentrated on the patient experience in the treatment of metastatic castration-resistant prostate cancer (mCRPC). He described a typical treatment timeline where a new patient presents with elevated PSA is initially treated with androgen deprivation therapy (ADP) to reduce testosterone feeding tumor growth. While the patient may initially respond with a reduced PSA, it is most common that the diseases will progress. The next line of treatment is usually with second-generation hormone therapy such as enzalutamide. The patient may show an initial improvement, but after about 11 months, the disease again progresses with increasing PSA and reduced quality of life. A similar timeline is observed with abiraterone (often combined with prednisone) instead of enzalutamide.

There have been studies of the sequential application of abiraterone/prednisone or enzalutamide followed by the other drug. The studies show no additional benefit of using both drugs sequentially although some clinicians still prescribe this regimen.

In the patient treatment timeline, there is a "gap" between the initial treatment of enzalutamide/abiraterone and the application of another treatment like the chemotherapy agent docetaxel. This gap is a natural place for treatment with Xofigo® (Radium-223 dichloride). Prostate cancer overwhelmingly metastasizes to the bone, and since radium is chemically similar to calcium, it is preferentially absorbed in rapidly growing bone tissue. Xofigo is effective in reducing tumor growth and relieving bone pain. It is well-tolerated in most patients. Dr. George noted that Xofigo doesn't have much effect on PSA or the androgen pathway. He felt that it was essential to explain this to patients who are otherwise puzzled that their PSA continues to rise even though the therapy is working.

Dr. George described a case study of a patient who showed a terrible bone scan in June 2013 but had a remarkable improvement by February 2014 after treatment with Xofigo.

Dr. George concluded by noting the trend for moving Xofigo earlier in the treatment timeline.

Presented by: Daniel J. George, MD, Medical Oncologist, Professor of Medicine, Professor of Surgery, Duke Cancer Institute, Durham, North Carolina