Effects of Radium-223 Dichloride on Total Alkaline Phosphatase (ALP) and Prostate-Specific Antigen (PSA) in Patients with Castration-Resistant Prostate Cancer (CRPC) and Symptomatic Bone Metastases from the Phase III ALSYMPCA trial

Presented at the 2014 European Association of Urology Annual Meeting

Abstract #865, 14 April, 12:15-1:45 PM CET,

Poster Session 70: Modern management of castration-resistant prostate cancer, Room A8

ALSYMPCA (ALpharadin in SYMptomatic Prostate CAncer) was a Phase ill, randomized, double-blind, placebo-controlled international study of radium-223 with best standard of care vs. placebo with best standard of care in symptomatic CRPC patients with bone metastases. Radium-223 compared with placebo significantly improved overall survival (OS) by 3.6 months and was well tolerated.


Radium-223 dichloride (Xofigcf) is the first alpha particle-emitting radioactive therapeutic agent approved by the European Commission for the treatment of adults with CRPC, symptomatic bone metastases and no known visceral metastases.

Xofigo is now approved in more than 30 countries worldwide.

Study Findings

  • Effects on ALP and PSA were assessed every 4 weeks through week 24, and then in continued follow-up visits for up to 3 years
  • Radium-223 decreased baseline ALP (32% J,) as compared to placebo, which experienced an increase from baseline ALP (37%|) (7.4 vs. 3.8 mo; HR=0.17; 95% Cl, 0.13-0.22; P<0.001)
  • Radium-223 patients who experienced ALP decline had significantly longer median overall survival than radium-223 patients without decline (17.8 vs. 10.4 mo; HR=0.45; 95% Cl, 0.34-0.61; PcO.0001)
  • PSA increased more rapidly among placebo patients than among radium-223 patients: median time to PSA progression was significzntly delayed in patients receiving radium-223 (HR=0,64: 95% Cl, 0,54-0,77;P<0,001)


  • Radium-223 significantly imroved overail survival in men with metastatic CRPC and has a major impact on ALP levels; the impact on PSA is relatively modest and PSA levels should not be used as a marker of response to radium-223
  • ALP requires further study as a possible biomarker response

What is ALP?

Alkaline phosphatase (ALP) is a protein present in a number of tissues including liver, bone, intestine and placenta. ALP can be elevated in disorders of the skeletal system that involve osteoblast hyperactivity and bone remodeling, such as hyperparathyroidism, fractures and malignant tumors.1

What is PSA?

Prostate-specific antigen (PSA) is a protein produced by cells of the prostate gland. The level of PSA is often elevated in men with prostate cancer, and the PSA test can be used to monitor the progression of prostate cancer in men who had already been diagnosed with the disease.2