CHICAGO, IL USA (UroToday.com) - Presented by A. Oliver Sartor, MD at the American Society of Clinical Oncology (ASCO) Annual Meeting - May 31 - June 4, 2013 - McCormick Place - Chicago, IL USA
Click HERE to view the poster from this session
Correlation between baseline variables and survival in the radium-223 dichloride (Ra-223) phase III ALSYMPCA trial with attention to total ALP changes
A. Oliver Sartor, Roy Amariglio, Scott Wilhelm, Jose E. Garcia-Vargas, C. Gillies O’Bryan-Tear, Minghua Shan, Fang Fang, Chris Parker
Tulane Cancer Center, New Orleans, LA; Bayer HealthCare Pharmaceuticals, Montville, NJ; Algeta ASA, Oslo, Norway; The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom
Background: In patients (pts) with castration-resistant prostate cancer and bone metastases (mCRPC), total ALP (tALP) has been shown to be a prognostic marker for overall survival (OS) (Cook 2006). Here the prognostic value of tALP and other baseline clinical variables in Ra-223 pts is presented, along with the initial results of an exploratory analysis of changes in tALP seen with Ra-223.
Methods: Study population included 921 pts (intent-to-treat population) from the ALSYMPCA trial. The Cox proportional hazards model was used to evaluate the prognostic potential of tALP and other baseline variables (albumin, Hb, LDH, ECOG performance status, PSA, and age). Log transformation was done for baseline variables (tALP, PSA, and LDH) with heavily skewed distributions. Baseline variables were assessed for interaction with treatment. To determine changes in tALP from baseline at 12 wk, 708 pts who had tALP measurements at both baseline and 12 wk were included.
Results: The baseline variables in the Table were significantly associated with OS. Hb was not a significant factor when adjusting for all other covariates and was therefore removed from the final Cox regression model. No significant treatment-by-covariate interactions were detected. After controlling for other variables, higher baseline tALP was significantly associated with an increased risk of death (p < 0.0001). At 12 wk, a decline in tALP relative to baseline was seen in 87% (433/497) of Ra-223 pts, compared to 23% (49/211) of placebo pts. The mean percentage change from baseline in tALP at 12 wk was a 32% decline for Ra-223 pts, in contrast to a 37% increase for placebo pts (p < 0.001).
Conclusions: In mCRPC pts, higher baseline levels of tALP were associated with an increased risk of death. With the majority of Ra-223 pts experiencing a decline in tALP at 12 wk, and the marked mean percentage tALP decline in these pts, further analysis to determine a correlation between tALP dynamics and survival is warranted. Clinical trial information: NCT00699751.
Dr. A. Oliver Sartor is a graduate of Tulane Medical School (1982) and was elected President of the AOA Honor Society. After completing residency in internal medicine at Tulane in 1986, he served as a fellow in the Medical Oncology Branch of the National Cancer Institute in Bethesda, Maryland. From 1990-1993 he served as a Senior Investigator at the National Cancer Institute in the Clinical Pharmacology Branch where he began to focus on novel therapeutics and clinical trials for advanced prostate cancer patients. He was the Director of the Stanley S. Scott Cancer Center, and served as Chief of the Hematology/Oncology Section at the Louisiana State University (LSU) Health Sciences Center in New Orleans from 1998-2006. After Hurricane Katrina, he departed New Orleans to join the Lank Center for Genitourinary Oncology at the Dana-Farber Cancer Institute/Harvard Medical School in Boston. He returned to Tulane Medical School in 2008 as the Piltz Professor of Cancer Research with a joint appointment in the Departments of Medicine and Urology. He has now been named the LaBorde Professor for Cancer Research. In 2010 he was appointed as the Medical Director of the Tulane Cancer Center.
Dr. Sartor’s research and clinical interests have focused broadly on prostate cancer over the past 20 years. His publications range from the genetic studies on prostate cancer, to studies of ethnic populations, to clinical trials involving novel agents. Among other duties, he is past-Chairman of the Integration Panel for the Department of Defense’s Congressionally Directed Medical Research Program in Prostate Cancer and the Medical Oncology Chairman of the GU Oncology Committee at the Radiation Therapy Oncology Group (RTOG). He has lead a number of large international trials in prostate cancer, including those leading to the FDA approval of samarium-153 EDTMP and cabazitaxel.