ASCO GU 2017: Radium-223 (Ra-223) in asymptomatic metastatic castration-resistant prostate cancer (mCRPC) patients treated in an international early access program (iEAP). - Poster Session Highlights
Orlando, Florida USA (UroToday.com) As Radium-223 is not approved for asymptomatic metastatic castration-resistant prostate cancer (mCRPC), this group of investigators sought to define the added benefit by employing the alpha targeting therapy earlier on in the disease course. Post-hoc analysis of a phase 3b prospective study comparing symptomatic vs. asymptomatic patients treated with Ra-223 demonstrated longer OS in the asymptomatic patients. As expected, the asymptomatic patients had favorable baseline clinicopathologic characteristics, were less often pre-treated with chemotherapy or androgen axis blockade, and completed Ra-223 at a higher rate.
Dr. Heidenreich stressed that the objective of the study was not to demonstrate that symptoms related to mCRPC was a prognosticator for survival, as this is invariably linked to other pre-treatment clinicpathologic characteristics. Instead, the lack of symptoms was used as a benchmark for early staged mCRPC, and that the use of Ra-223 in these patient provided added benefit. This finding is reminiscent of the important findings of the added benefit with using docetaxel in the androgen sensitive setting in metastatic prostate cancer by the CHAARTED and STAMPEDE trials.