In a retrospective study of 308 patients conducted with the University of New
Mexico Cancer Research and Treatment Center at the Health Sciences Center,
Exagen Diagnostics, an emerging leader in the rapid identification and
productization of practical, genomic markers for prognostic testing, reported
the discovery of two, 3-gene sets of markers that were prognostic in testing
archived specimens from hormone receptor (HR)-positive and hormone
receptor-negative patients, respectively. These two sets of markers form a panel
for use in testing tumor tissue from breast cancer patients, providing a same-
or next-day result.
In independent test sets, each of the 3-gene markers accurately identified 91
percent of HR-negative and HR-positive specimens from patients that did not
experience recurrence of disease. In patients that were also node negative, the
negative predictive value was 100 percent (e.g., 100 percent of patients
identified by these tests had a good prognosis clinically).
The study population consisted of white and Hispanic patients with invasive
ductal carcinoma that were diagnosed between 1986 and 1999 at the University of
New Mexico Health Sciences Center. A minimum of four years of follow-up clinical
information was available for each of the patients, with an average follow-up of
8.9 years. Poor prognosis was clinically defined as development of recurrence,
as evidenced by either distant metastasis or death from breast cancer. Good
prognosis was clinically defined as the absence of recurrence (or death from
breast cancer) as of the last date of follow-up.
"With this approach, we are seeking to define a new standard of care by
becoming the first company to offer a prognostic panel of tests that examines
the patient's tumor tissue to detect changes in DNA copy number in any patient.
This is a more practical method than currently available tests using RNA," said
Waneta Tuttle, Ph.D., Exagen CEO.
"Today, we are treating almost any woman as though her cancer is aggressive,
which puts patients who don't actually need treatment at risk for side-effects
of therapy that is not necessary," explains Ian Rabinowitz, M.D., the primary
UNM clinician involved in Exagen's initial study. "For early stage breast cancer
there are about 70 to 80 percent of patients who are cancer-free and don't
actually require therapy after they receive a lumpectomy. At this point in time,
we have no way of identifying which patients fall into that category. So, the
advantage of a technology such as Exagen's prognostic tests, once it is further
validated, is that we can better identify patients that have a very good
prognosis and potentially don't actually require therapy," he said.
The study was conducted using a proprietary "pattern of genomic
amplification" FISH (e.g., fluorescent in situ hybridization) test or PGA
FISH(TM). Due to the small number of markers in each reagent set, Exagen is
uniquely able to implement these tests with PGA FISH technology, making them
readily usable by any FISH-testing laboratory. Exagen's discovery technology is
based on a mathematical approach that enables the company to examine 25,000
genes with no "preference" for one gene over another to define the best, small
combination of genes for a specific testing purpose.
About Exagen Diagnostics, Inc.
As an emerging leader in prognostic testing, Exagen Diagnostics is uniquely
able to define small sets of genomic markers that are more accurate than other
approaches, whether for breast cancer, infectious disease or other indications.
Exagen's proprietary discovery and implementation technologies enable the rapid
identification and productization of optimized DNA or RNA genomic marker sets
for prognostic or predictive testing, either for diagnostic testing by reference
laboratories or for pharmaceutical R&D purposes
