Radium-223 plus abiraterone in metastatic castration-resistant prostate cancer: a cautionary tale
Metastatic castration-resistant prostate cancer (mCRPC) spreads to bone in up to 90% of patients and can be associated with pain, skeletal-related events (SREs), reduced mobility with quality of life impairment, and shortened overall survival (OS) (1-4). Over the past several years, treatment options for mCRPC have expanded, and now include cytotoxic agents (docetaxel, cabazitaxel), oral hormonal therapies targeting the androgen receptor (abiraterone, enzalutamide, apalutamide), targeted alpha-particle therapy (radium-223), immunotherapy (sipuleucel-T), and bone-supportive agents (zoledronate, denosumab) that reduce SREs (5-7). It is not yet clear, however, how to sequence or combine available agents in routine clinical practice. Bone disease remains a leading contributor of morbidity and mortality for patients with metastatic prostate cancer. Researchers thus continue to search for novel combinations of proven therapies to improve survival and quality of life for these patients. This was the intention of the ERA-223 study (NCT02043678), a trial that investigated a novel combination of radium-223 dichloride with abiraterone acetate.