Researchers presented the first comprehensiveresults of Neoprobe
Corporation's pivotal multicenter studies of its RIGScan product
at The Society of Surgical Oncology's (SSO) 49th Annual Cancer
Symposium in Atlanta on March 22. The product is used with Neoprobe's
proprietary RIGS technology for surgical detection of metastatic
colorectal cancer. The RIGS system consists of cancer-specific
targeting agents, such as RIGScan CR49, hand-held gamma detectors,
and methods for their use.
The results of the clinical trials were reported at a special
symposium entitled "Strategies to Lessen Our Current Failure
Rate in Colorectal Cancer" held at the SSO meeting. The panel
presentation was moderated by Kirby I. Bland, MD, of Brown University
School of Medicine, who is also a member of Neoprobe's Scientific
Advisory Board. Four other leading cancer researchers participated
in the symposium.
"This symposium continues our efforts to keep our members
informed about the latest theories and treatments for colorectal
cancer," said Dr. Bland, who was recently elected President
of the SSO. "Although the incidence of colorectal cancer
in the United States has decreased slightly, it is ranked third
highest in causing cancer deaths. Almost half of patients die
of the disease. Surgery is still the most effective treatment.
New research and innovative techniques are the best hope for improving
our ability to treat these patients successfully."
Speakers joining Dr. Bland in the symposium panel included Isaiah
Fidler, phd, University of Texas M.D. Anderson Cancer Center,
who spoke on "The Metastatic Cancer Cell," Glenn Steele,
MD, PhD, Pritzger School of Medicine, University of Chicago, who
discussed "Molecular Mechanisms in Tumor Growth", John
Daly, MD, New York Hospital, Cornell University Medical Center,
who provided a "RIGS Clinical Update," and
Jeffrey Schlom, PhD, National Institutes of Health, National Cancer
Institute, who talked about "Future Carriers and Current
Strategies to Upregulate Antigen Expression."
Results of Pivotal Trials in Metastatic Colorectal Cancer
Dr. Daly's talk included the first announced results of Neoprobe's
trials involving metastatic colorectal cancer patients at 24 cancer
centers and hospitals in the United States, Europe, and Israel.
The RIGS procedure helped surgeons find additional cancer in one
out of every five evaluable patients (those who had biopsy-proven
localized tumor and who completed the study). The additional tumor
was confirmed by conventional pathologic tests. Both a CT scan
and the surgeon had missed the tumor found by the RIGS system.
Using this new information, surgeons changed surgical management
decisions for most of the patients who had an additional RIGS-located
tumor. Surgical management changes included removal of more disease,
abandoning the surgery if disease was found to be too widespread,
or removing more tissue at the edges of the tumor in an effort
to ensure complete removal.
"Optimal treatment for each patient depends on knowing the
full extent of the patient's cancer," Dr. Daly stated. "When
the RIGS system gives more information than ordinarily is available,
surgeons are able to individualize treatment for those patients
The results of these pivotal clinical trials, along with those
of previous studies with the same targeting agent for metastatic
colorectal cancer, are the basis for Neoprobe's marketing applications
for the company's first RIGS product. The applications are planned
for submission in Europe and the United States. Neoprobe is currently
involved in discussions and review of the phase III data with
The company's full analysis of the pivotal trials will be completed
upon submission of the marketing applications for RIGScan CR49.
These trials are called "pivotal" because they are the
last of a sequence of trials conducted to show the safety and
effectiveness of a drug or biologic.
The RIGS system, a new diagnostic tool for surgeons, works by
injecting a cancer patient before surgery with a low-level radioactive,
cancer-specific targeting agent. During the operation, the surgeon
uses the RIGS gamma-radiation-detecting probe to locate tissue
that contains a significant amount of the radioactive targeting