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The NCI/FDA Proteomics Research Program, Its Research, and Diagnostic Tests by Private Industry (e.g., OvaCheck): Fact Sheet
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What was the National Cancer Institute/U.S. Food and Drug Administration
Clinical Proteomics Program?
A collaboration between the National Cancer Institute (NCI) and the U.S. Food
and Drug Administration (FDA) began in 1997 and was led by Lance Liotta, M.D.
Ph.D., formerly of NCI's Center for Cancer Research, and Emanuel Petricoin,
Ph.D., formerly of FDA's Center for Biologics Evaluation and Research (CBER).
Liotta and Petricoin left NCI and FDA in 2005 and are now at George Mason
University, Fairfax, Va., where they are heading a newly formed Proteomics
Institute. With the departures of Liotta and Petricoin, opportunities and
mechanisms for interactions between the agencies are being evaluated.
The NCI/FDA proteomics program was originally conceived with the scientific
goal of applying proteomics techniques to cancer in order to understand the
flow of information within the cell and the organism. Petricoin and Liotta
developed new technologies to analyze the molecular networks of diseased and
normal cells. These technologies included the use of tissue specimens to
develop tools for protein fingerprinting.
Potential benefits of clinical proteomics include developing individualized
therapies using targeted treatments that could be predetermined to be effective
for each patient; determining the toxic and beneficial effects of treatments in
the lab before using them in patients; diagnosing cancer earlier than is now
possible; and improving the understanding of tumors at the protein level,
possibly leading to better treatments.
Liotta and Petricoin developed a new type of protein microarray to analyze the
molecular network, or the cellular "circuitry", of cancer cells from a biopsy
specimen using and a large panel of validated antibodies that specifically
recognized proteins that are phosphorylated (have a phosphate group attached to
them). Using this approach, researchers study how a particular treatment
changes the network, or circuitry, of proteins in a cell and how signaling
pathwasy change if a tumor returns after treatment. Additionally, laser capture
microdissection (LCM) was invented in Liotta's laboratory in 1996 and allows
the isolation of pure normal cells, pre-cancerous cells, and tumor cells, if
present, from the same biops for proteomics analysis.
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What was the association between NCI/FDA research and the OvaCheck test for
ovarian cancer that was being developed by private industry?
The former NCI/FDA proteomics program was not involved with the development of
OvaCheck. It was independently developed by Correlogic Systems in conjunction
with Quest Diagnostics and LabCorp, two non-governmental, private companies.
Data posted or published by the NCI/FDA program was not used to assess or judge
tests developed using different technology. OvaCheck was unrelated to
previously published work between Correlogic and the NCI/FDA, and utilized
different mass spectrometry instrumentation and detection methods, as well as
different sample handling and processing methods.
Scientists at FDA and NCI cannot comment on the work done independently by
Correlogic (and specifically OvaCheck ) since they are not involved with, nor
are they privy to, proprietary corporate data.
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Did the NCI/FDA proteomics program develop a test for the detection of ovarian
cancer of their own?
Neither the NCI nor the FDA conducted research to develop a "test" for the
detection of ovarian cancer. The NCI/FDA Proteomics Program conducted a series
of research studies to examine the hypothesis that proteomic patterns are
different in cancer versus control samples. The program worked to refine,
improve, and optimize its techniques, to validate the test results, and to
identify and sequence the diagnostically important molecules which underpin
mass spectrometry readings.
The NCI/FDA Proteomics Program did not work on the development of a commercial
test to be used in patients to detect ovarian cancer. It was not involved in
the marketing of any early detection tests.
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The NCI/FDA proteomics program looked for biomarkers that are diagnostic for
cancer. Doesn't that mean that they want to develop a test for earlier
detection of cancer?
The NCI/FDA proteomics program was involved in validating their techniques,
analyzing data, repeating experiments, and optimizing methods. These are all
research activities that must be done in a deliberate, step-wise progression
and must be rigorously validated before a diagnostic tool or treatment could be
developed.
A research paper, published in The Lancet in February, 2002, reported a
feasibility study. It described an approach, whereby mass spectrometry
generated fingerprints (unique identifiers) derived from low molecular weight
molecules could discriminate between a study set of ovarian cancer tumors and
specimens from healthy high risk women. Neither the paper, nor the molecules
described, were the basis of any test; rather they were a description of an
approach. Prospective clinical trials to stringently test the hypothesis have
been designed and will have to be completed prior to development and marketing
of a diagnostic test.
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What are biomarkers and how are they identified and validated for use in the
clinical setting?
Biomarkers are molecules that exist naturally in the body that can help predict
or reflect the presence of a disease, the risk of relapse of the disease,
and/or response to treatment.
Successfully translating research on biomarkers from the laboratory to patients
involves five phases:
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Phase 1 includes exploratory studies to identify potentially useful biomarkers
-- this is called the discovery phase.
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Phase 2 is where biomarkers are studied to determine their capacity for
distinguishing between people with cancer and those without -- the validation
phase.
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Phase 3 determines the capacity of a biomarker to detect pre-clinical disease
by testing the marker against tissues collected longitudinally from research
cohorts.
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Phase 4 includes prospective screening studies.
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Phase 5 is when large-scale population studies evaluate not just the role of
the biomarker for detection of cancer, but the overall impact of screening on
the population and whether this screening impacts survival.
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Have government researchers made any efforts to standardize research protocols,
procedures and technology so that proteomic results obtained at the NCI or FDA
would be comparable to those in other labs nationwide?
In June 2005, NCI's Board of Scientific Advisors (BSA) approved a Clinical
Proteomics Technologies Initiative, a $104 million program aimed at optimizing
current proteomics technologies and developing new technologies, reagents, and
systems to significantly advance the field of cancer proteomics research. This
Initiative is not specific to the National Institutes of Health Bethesda
campus, which housed the program in which Petricoin and Liotta worked and Elise
Kohn, M.D., currently works. Rather, it is open to the broad cancer research
community. The initiative builds on a two year process that sought feedback
from the research community through workshops and meetings.
The initiative encompasses a three-pronged strategy:
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Establishment of Clinical Proteomic Technology Assessment Consortia, which will
focus on evaluating tools, such as proteomic technologies and reference
reagents; develop protocols and perform cross-laboratory studies of common
sample sets; and also provide consultative services and training to the
community.
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Support of research into overcoming barriers to protein/peptide feature
detection, identification, and quantification; and development of mathematical,
computational, and predictive approaches for analysis of large scale data.
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Creation of an online, centralized clinical proteomics reagents resource, which
will include resources such as antibodies, peptides, and proteins.
NCI is also involved in another major initiative -- the National Biospecimen
Network. NCI's Biospecimen Coordinating Committee is preparing a report on the
development of standards for the collection of biospecimens. These standards
will assure that the highest-quality material is going toward high-end and
sensitive advanced technologies thus making cross-comparisons possible because
high-quality starting material is used for endpoint assays.
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What additional proteomics research contributed to the current proteomics tools
and what is planned next?
Besides ovarian cancer, similar techniques are being applied to other cancers.
Researchers are looking for protein patterns and identified carrier
protein-bound molecules in the blood that are diagnostic for early-stage
aggressive prostate, lung, and breast cancers, as well as patterns that can
predict risk for prostate, colon, skin, and pancreatic cancers.
The general strategy of proteomics research is to analyze proteins from the
blood or tissue with mass spectrometry and protein microarrays to identify
important changes that occur in the progression from normal to disease. The
ultimate goal is to use this information for earlier detection of cancer,
patient-tailored therapy, and more effective therapeutic monitoring.
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What is the clinical trial that NCI is sponsoring in the area of ovarian cancer
diagnosis?
A NCI-sponsored ovarian cancer clinical trial, involving ten sites, is
scheduled to start in Fall 2005. Because over 80 percent of advanced stage
epithelial ovarian cancer patients see their cancer return after being treated
with standard chemotherapy, biomarkers are needed for predictors of persistent
disease and relapse. CA-125, the only FDA-approved ovarian cancer relapse
marker, will become elevated in some, but not all, of the approximately 80
percent of advanced stage patients for whom it was increased at initial
diagnosis. Elevation in CA-125 may precede clinical evidence of relapse by as
much as six to 10 months or lag behind clinical relapse by the same time
intervals, making it a less than satisfactory clinical tool.
Researchers have identified a pattern of proteins that sensitively and
specifically recognizes the presence of ovarian cancer (stages I-IV) in blood
from affected women. Furthermore, the pattern can distinguish between affected
women and unaffected women and those with the presence of non-malignant
disease. Investigators hypothesize that significant changes in proteomic
signature patterns can be defined and that these will be reliably predictive of
relapse. Further, they hypothesize that the protein signature pattern changes
will be as good as, or better than, CA125 as a single marker alone or in
combination with CA125 monitoring. A serum repository of samples from women
with ovarian cancer will be created in order to develop and validate the
multiple biomarkers and proteomics tests being created for ovarian cancer
recurrence and screening.
The purpose of this protocol is to determine sensitivity and specificity for
detection of cancer in patients who are in remission for their disease. This
study is an expansion of the trial opened to patient participation in 2000 by
Dr. Kohn and called the "Pilot Study of Proteomic Evaluation of Epithelial
Ovarian Cancer Patients In First Clinical Remission: Development of a Protein
Fingerprint Profile Associated With Relapse", NCI 00-C-0018. The earlier study,
conducted solely at NIH in Bethesda, Md., has enrolled 25 or more patients
towards a ceiling of 40. Patients are followed up to every three months. At
each visit they undergo an evaluation and examination by the medical team, have
routine laboratory and CA125 tests done, have a CT scan to see if there is
evidence of recurrent cancer, and have a vial of blood taken to be stored for
use in development of a pilot proteomics pattern. This trial will close when
the new multi-institutional, multi-state study opens shortly. The
multi-institutional trial will also follow patients every 3 months with exam,
laboratory test, and CA125 and every other visit, a CT scan.
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What are the mortality and survival rates associated with ovarian cancer?
Ovarian cancer is the fifth most common cancer in women and the leading cause
of death in the U.S. from gynecologic malignancies. Approximately 25 percent of
patients are diagnosed when ovarian cancer is localized to the ovary. Up to 90
percent of these very early cancers can be successfully treated, while only 30
percent of the patients with more advanced cancers will survive five years.
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