Real-world patient characteristics associated with survival of 2 years or more after radium-223 treatment for metastatic castration-resistant prostate cancer (EPIX study).

Abstract

BACKGROUND:

The real-world EPIX study was conducted to gather information about the characteristics of patients with metastatic castration-resistant prostate cancer (mCRPC) who survived ≥2 years after treatment with the alpha-emitter radium-223.

METHODS:

This retrospective study of electronic health records in the US Flatiron database (NCT04516161) included patients with mCRPC treated with radium-223 between January 2013 and June 2019. Median overall survival (OS) and prostate-specific antigen (PSA) response (≥50% reduction) from start of radium-223 treatment were the primary and secondary endpoints, respectively. Patient characteristics were compared between those who survived ≥2 years versus <2 years, including a subgroup who survived <6 months.

RESULTS:

In the 1180 patients identified, median OS was 12.9 months (95% CI: 12.1-13.7), and 13% of patients with data at 6 months had a PSA response. The survival groups included 775 patients (65.7%) who survived <2 years (including 264 (22.4%) who survived <6 months) and 185 patients (15.7%) who survived ≥2 years; 220 patients (18.6%) had incomplete follow-up data and were censored. On multivariate analysis, age >75 years, Eastern Cooperative Oncology Group performance status (ECOG PS) 2-4, visceral metastases, prior symptomatic skeletal events (SSEs), and prior chemotherapy were independently prognostic of reduced OS. For patients with survival ≥2 years versus <2 years, median age was 71 versus 75 years, 4% versus 14% had ECOG PS 2-4, 4% versus 10% had visceral metastases, 38% versus 44% had prior SSEs, and 16% versus 32% had prior chemotherapy.

CONCLUSIONS:

In this study of men with mCRPC treated in real-world clinical practice, median OS was consistent with that seen in the phase 3 ALSYMPCA trial. Patients who survived ≥2 years after the start of radium-223 were younger and had better ECOG PS, lower disease burden, and less use of prior chemotherapy than those who survived <2 years.

• Authors: Daniel J George, Neeraj Agarwal, Oliver Sartor, Cora N Sternberg, Bertrand Tombal, Fred Saad, Kurt Miller, Niculae Constantinovici, Helen Guo, John Reeves, XiaoLong Jiao, Per Sandström, Frank Verholen, Celestia S Higano, Neal Shore
• Journal: Prostate cancer and prostatic diseases (Prostate Cancer Prostatic Dis) Vol. 25 Issue 2 Pg. 306-313 (02 2022) ISSN: 1476-5608 [Electronic] England
• PMID: 35190653 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2022. The Author(s).

Chemical References

• Radioisotopes
• Radium-223
• Prostate-Specific Antigen
• Radium

Topics

• Aged
• Bone Neoplasms (secondary)
• Humans
• Male
• Prostate-Specific Antigen
• Prostatic Neoplasms, Castration-Resistant (drug therapy)
• Radioisotopes (therapeutic use)
• Radium (therapeutic use)
• Retrospective Studies
• Treatment Outcome