Concurrent or layered treatment with radium-223 and enzalutamide or abiraterone/prednisone: real-world clinical outcomes in patients with metastatic castration-resistant prostate cancer.

Abstract

BACKGROUND:

In this study, we evaluated real-world data on radium-223 plus abiraterone/prednisone or enzalutamide. Previously, the ERA 223 trial (NCT02043678) demonstrated increased fracture risk with concurrent treatment with radium-223 and abiraterone plus prednisone/prednisolone in patients with metastatic castration-resistant prostate cancer (mCRPC).

METHODS:

We used the Flatiron Health database to perform a retrospective study of patients with mCRPC treated with radium-223. Treatment with radium-223 plus abiraterone/prednisone or enzalutamide was defined as concurrent if both drugs started within 30 days of one another, or layered when the second drug started ≥30 days after the first. The index date was defined as the day of the first radium-223 dose. Outcome measures included symptomatic skeletal events (SSEs), overall survival (OS), and patterns of treatments received.

RESULTS:

Of the 625 patients treated with radium-223, 22% received it together with abiraterone/prednisone and 27% with enzalutamide. When these agents were combined, they were often initiated in a layered fashion (73% layered, 23% concurrent). Prior or concomitant bone health agents (BHAs) were received by 67% and 55% of patients, respectively. Median follow-up was 9 months. Overall, incidence rates for SSEs and pathologic fractures were 0.35 and 0.11 patients per person-year, respectively. Median OS from mCRPC diagnosis was 28.1 months.

CONCLUSIONS:

In this real-world setting, combination treatments with radium-223 and abiraterone/prednisone or enzalutamide were common. These agents were more commonly given in a layered than a concurrent fashion. Incidence rates for SSEs were reduced when BHAs were used; however, BHAs were underutilized.

• Authors: Neal Shore, Celestia S Higano, Daniel J George, Cora N Sternberg, Fred Saad, Bertrand Tombal, Kurt Miller, Jan Kalinovsky, XiaoLong Jiao, Krishna Tangirala, Oliver Sartor
• Journal: Prostate cancer and prostatic diseases (Prostate Cancer Prostatic Dis) Vol. 23 Issue 4 Pg. 680-688 (12 2020) ISSN: 1476-5608 [Electronic] England
• PMID: 32404868 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Androstenes
• Benzamides
• Bone Density Conservation Agents
• Nitriles
• Phenylthiohydantoin
• Denosumab
• Zoledronic Acid
• Radium-223
• enzalutamide
• abiraterone
• Prednisone
• Radium

Topics

• Adult
• Aged
• Aged, 80 and over
• Androstenes (administration & dosage)
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Benzamides (administration & dosage)
• Bone Density Conservation Agents (therapeutic use)
• Bone Neoplasms (drug therapy, secondary)
• Chemoradiotherapy
• Clinical Trials, Phase III as Topic
• Denosumab (therapeutic use)
• Humans
• Male
• Middle Aged
• Multicenter Studies as Topic
• Neoplasm Metastasis
• Nitriles (administration & dosage)
• Phenylthiohydantoin (administration & dosage)
• Prednisone (administration & dosage)
• Prostatic Neoplasms, Castration-Resistant (drug therapy, pathology)
• Radium (therapeutic use)
• Randomized Controlled Trials as Topic
• Retrospective Studies
• Survival Rate
• Treatment Outcome
• Zoledronic Acid (therapeutic use)