Declines in alkaline phosphatase (ALP) may predict better outcomes in patients receiving treatment with radium-223 for metastatic castration-resistant prostate cancer (mCRPC), according to study findings presented at the European Society for Medical Oncology 2016 congress in Copenhagen.
As part of a prospective single-arm phase 3b study, investigators led by Daniel Heinrich, MD, of Akershus University Hospital in Lorenskog, Norway, studied 696 mCRPC patients who received at least 1 radium-223 cycle in an international early access program. At week 12, 398 patients (57%) had a confirmed decline in ALP from baseline and 298 (43%) did not.
Compared with the group that did not have an ALP decline, the group that did had a significant 70% decreased risk of death and a 53% decreased risk of first symptomatic skeletal event, Dr Heinrich and his colleagues reported.
More patients with a confirmed ALP decline received 5–6 radium-223 injections than those with no ALP decline (94% vs 33%).
The investigators noted that identifying a reliable marker of efficacy for radium-223 would help in the clinical management of mCRPC patients.
1. Heinrich D, et al. Changes in alkaline phosphatase (ALP) dynamics and overall survival (OS) in metastatic castration-resistant prostate cancer (mCRPC) patients treated with radium-223 in an international early access program (EAP). Findings presented at the European Society for Medical Oncology 2016 congress in Copenhagen, October 7–11. Poster 751P. Ann Oncol 2016;27(Suppl 6):vi257.