ORLANDO, FL, USA (UroToday.com) - In this session, the authors presented data from the ALSYMPCA trial related to use of external beam radiation therapy (EBRT) with radium-223 dichloride in patients with metastatic castration-resistant prostate cancer (mCRPC). The ALSYMPCA trial was a phase III randomized, double-blind, placebo-controlled trial published in 2013 which demonstrated an overall survival benefit with the administration of radium-223 to men with mCRPC with multiple symptomatic bony metastases. The poster presentation was a post hoc analysis of the ALSYMPCA trial.
The authors reported that 50% of study participants underwent EBRT prior to randomization. These patients had greater disease burden and resulting higher WHO pain scores. Following randomization, patients who received radium-223 demonstrated significantly lower use of concomitant EBRT compared to placebo. EBRT use for bone pain was reduced by 33% in the radium-223 group compared to placebo. Subgroups demonstrating decreased EBRT use with radium-223 compared to placebo included those with 20 bony metastases or less (HR 0.49, 95% CI 0.36-0.66, p < 0.0001), those currently on bisphosphanates (HR 0.47, 95% CI 0.30-0.72, p=0.004), and those with total alkaline phosphatase level less than 220 U/L (HR 0.66, 95% CI 0.48-0.90, p=0.008). The study also found that EBRT did not increase adverse events related to radium-223, including rates of myelosuppression.
This data is further proof of the efficacy of radium-223 in mCRPC patients with symptomatic bony metastases. The lack of additive adverse events when EBRT is combined with radium-223 is reassuring, and not trivial, given that 20-30% of patients, as reported by the study, will still require concomitant EBRT therapy within the first 12 months on radium-223.
Presented by Stephen E. Finkelstein, Jeff M. Michalski, Joe M. O’Sullivan, Chris Parker, Jose E. Garcia-Vargas, and A. Oliver Sartor at the 2015 Genitourinary Cancers Symposium - "Integrating Biology Into Patient-Centric Care" - February 26 - 28, 2015 - Rosen Shingle Creek - Orlando, Florida USA
21st Century Oncology, Scottsdale, AZ, USA; Washington University School of Medicine, St Louis, MO, USA; Centre for Cancer Research and Cell Biology, Queen’s University, Belfast, UK; The Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, UK; Bayer HealthCare, Whippany, NJ, USA; Tulane Cancer Center, New Orleans, LA, USA
Reported by Timothy Ito, MD, medical writer for UroToday.com
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