Bayer recently announced, however, that an Independent Data Monitoring Committee recommended unblinding of the phase 3 ERA223 trial (ClinicalTrials.gov Identifier: NCT02043678) of radium-223 in combination with abiraterone acetate and prednisone/prednisolone in prostate cancer.3 According to the press release, the recommendation was made because of an observed imbalance of more fractures and deaths in the combination arm in patients with asymptomatic or mildly symptomatic, chemotherapy-naive metastatic CRPC.
Dr Sartor said that although the expanded access program demonstrated safety, until the ERA223 trial is unblinded and he has additional opportunities to examine what the data show, it will be impossible to comment on the implications.
Looking at the combination of radium-223 and enzalutamide, there is still an ongoing prospective randomized trial assessing the safety and efficacy of the combined treatment.
“The question remains, how do the older findings about radium-223 apply in this newer landscape in an era when most patients get abiraterone or enzalutamide?,” Dr Sartor asked. “We just don’t have the data at this point.”
- Parker C, Nilsson S, Heinrich D, et al. Alpha emitter radium-223 and survival in metastatic prostate cancer. N Engl J Med. 2013;369:213-23.
- Sartor O, Vogelzang NJ, Sweeney C, et al. Radium-223 safety, efficacy, and concurrent sue with abiraterone or enzalutamide: first U.S. experience from an expanded access program. Oncologist. 2017 Nov 28. doi: 10.1634/theoncologist.2017-0413 [Epub ahead of print]
- Phase III trial of radium Ra 223 dichloride in combination with abiraterone acetate and prednisone/prednisolone for patients with metastatic castration-resistant prostate cancer unblinded early [news release]. Whippany, NJ: PRNewswire; November 30, 2017. https://www.prnewswire.com/news-releases/phase-iii-trial-of-radium-ra-223-dichloride-in-combination-with-abiraterone-acetate-and-prednisoneprednisolone-for-patients-with-metastatic-castration-resistant-prostate-cancer-unblinded-early-300564844.html. Accessed December 7, 2017.