ORLANDO, FL--(Marketwire - February 27, 2009) - Dana-Farber Cancer Institute (DFCI) and Source
MDx today announced that Source MDx's whole blood RNA transcript-based
Precision Profiles™ diagnostic test predicted survival in men with
castration-resistant prostate cancer (CRPC). In a study of 62 CPRC
patients, the model separated patients into a high risk group (survival
less than 2.2 years) and a low risk group (survival greater than 2.2 years)
(log rank p=0.00083). The six-gene CRPC Precision Profile™ was 96
percent accurate in predicting low risk CRPC patients alive at study end
and 93 percent accurate in predicting high risk CRPC patients who died
prior to study completion, suggesting that the model may be a powerful tool
for stratifying CRPC patients in clinical trials. The Prostate Cancer
Clinical Trials Consortium (PCCTC) will begin a prospective, multisite
clinical trial to validate using Source MDx's six-gene CRPC Precision
Profile™ to stratify aggressive vs. non-aggressive CPRC patients.
In the study, circulating tumor cell (CTC) counts were not predictive of
survival. In fact, the highest CTC counts (931 and 263) were found in
patients from the low risk group. The Halabi nomogram, a commonly used
clinical prognostic factor that uses seven clinical measures, also
predicted low and high risk groups of men with CRPC, based on evaluations
in 56 patients, but was less discriminatory (p=0.012) than the six-gene
Precision Profile™.
William K. Oh, M.D., clinical director, Lank Center for Genitourinary
Oncology, DFCI today presented the data from abstract 176 in a general
poster session at the American Society for Clinical Oncology's
Genitourinary Cancers Symposium. The study was co-investigated with Robert
W. Ross, M.D., attending physician, Lank Center for Genitourinary Oncology,
DFCI.
The PCCTC, a national clinical research group comprised of top U.S.
research institutions, including DFCI, will conduct a prospective
multi-site validation clinical trial of CRPC patients under the leadership
of Dr. Oh. Consortium studies focus on the evaluation of novel agents for
the management of prostate cancer at all stages of the disease. Source MDx
has filed provisional patents on the six-gene model, which also states
diagnostic claims for protein markers corresponding to patented RNA
transcripts.
"Survival for castration-resistant prostate cancer ranges greatly from
several months to several years, however, there are no available tools that
allow clinicians to easily identify patients with the most aggressive form
of the disease," commented Dr. Oh. "The ability to identify patients with
more aggressive forms of castration-resistant prostate cancer using a
simple blood assay may prove to be a powerful tool for stratifying patients
in clinical trials, leading to more robust studies with more relevant
survival endpoints. I look forward to further evaluating this
biologically-based test in forthcoming larger, multi-site clinical trials
with the Prostate Cancer Clinical Trials Consortium."
These data also show that individual differences in gene transcripts
associated with cell-mediated and humoral immunity are associated with
survival in CRPC patients. These specific immune system changes were
indicative of a decrease in both cell-mediated and humoral immunity in CRPC
patients with higher mortality.
"The six genes predictive of more lethal castration-resistant prostate
cancer in this trial suggest a fundamental difference in a patient's immune
system's ability to deal with malignant tumors when confronted with more
aggressive forms of prostate cancer," stated Karl Wassmann, Chief Executive
Officer of Source MDx. "The Source MDx six-gene CRPC Precision Profile™
is now available for patient stratification in prostate cancer clinical
trials."
About the Study:
From August 2006 through June 2008, Source MDx and Dana-Farber Cancer
Institute conducted a study to discover whole blood-based RNA-transcript
biomarkers predictive of primary end-points of CRPC progression (i.e.,
survival). The study enrolled a total of 62 CRPC patients, with or without
bone metastases, who had previously undergone a variety of treatments,
including hormone therapy, chemotherapy and radiation. Each patient
consented to the collection of whole blood in PAXgene™ blood RNA tubes
for gene expression and CellSave™ tubes for the enumeration of
circulating tumor cells (CTCs).
Using Source MDx Precision Profiles™, a total of 168 inflammation and
prostate cancer-related genes were evaluated using optimized Q-PCR
technology to assess biomarkers predictive of survival. Hazard ratio
survival analysis models were performed on a weekly basis, both from the
time of CRPC diagnosis through June 20, 2008 and from the time of blood
draw through June 20, 2008. The results were similar regardless of the
survival time definition (the time of castration-resistant diagnosis vs.
blood draw) or the survival model used for statistical analysis. Treatment
type was not predictive of survival.
About Prostate Cancer:
Prostate cancer is the most common cancer, other than skin cancers, in
American men and is the second leading cause of cancer death in men behind
only lung cancer. The American Cancer Society estimates that during 2008
about 186,320 new cases of prostate cancer will be diagnosed in the United
States. Tumors that are no longer responsive to hormone therapy are
referred to as castration-resistant. Mean survival for CRPC is
approximately 4.5 years, ranging from several months to more than eight
years. Treatment options include hormone therapy, chemotherapy, and
radiation.
About Source MDx:
Source MDx, the leader in RNA transcript-based molecular diagnostics, uses
its patented technology to monitor an individual's health, disease status
and response to therapy at the molecular level. The company is
demonstrating how the link between cancer and the immune response can be
translated into whole blood RNA transcript-based prognostic, predictive and
early detection oncology biomarkers. Source is currently collaborating
with leading academic institutions such as Dana-Farber Cancer Institute,
NYU Medical Center and Brigham and Women's Hospital. Source MDx also has a
translational molecular medicine collaboration with Pfizer, Inc. to develop
and validate RNA-based pharmacodynamic and predictive biomarkers within
Pfizer's cancer and inflammation therapeutic development programs for
commercialization as companion diagnostics. Source MDx has patented
Precision Profile™ biomarkers in nine cancers including prostate, lung,
and melanoma, and eight autoimmune diseases, including multiple sclerosis.
The company has completed over 150 preclinical and clinical projects for
more than 30 leading pharmaceutical, biotechnology and diagnostic
companies. Source has offices in both Boulder, Colorado and Newton,
Massachusetts. For more information, please visit www.sourcemdx.com.
About The Prostate Cancer Clinical Trials Consortium:
The Prostate Cancer Clinical Trials Consortium (PCCTC) offers simplified
solutions for multicenter clinical studies by bringing together leading
prostate cancer investigators from the top research institutions across the
country for the rapid design, development, and implementation of early
phase prostate cancer clinical trials. Capitalizing on the scientific
expertise and unique institutional resources, PCCTC members work together
to address barriers to the timely execution of clinical trials. Coordinated
scientific priorities, standard protocol and contract language and
centralized data management allows the PCCTC to evaluate needed therapies
more efficiently. The infrastructure of the PCCTC is funded and supported
by the Department of Defense Clinical Consortium Award. For more
information, please visit www.pcctc.org.
