Neoprobe Reports Initial Results of Multicenter Trials of Colorectal Cancer Detection System

May 1, 1996

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.

Researchers presented the first comprehensiveresults of NeoprobeCorporation's pivotal multicenter studies of its RIGScan productat The Society of Surgical Oncology's (SSO) 49th Annual CancerSymposium in Atlanta on March 22. The product is used with Neoprobe'sproprietary RIGS technology for surgical detection of metastaticcolorectal cancer. The RIGS system consists of cancer-specifictargeting agents, such as RIGScan CR49, hand-held gamma detectors,and methods for their use.

The results of the clinical trials were reported at a specialsymposium entitled "Strategies to Lessen Our Current FailureRate in Colorectal Cancer" held at the SSO meeting. The panelpresentation was moderated by Kirby I. Bland, MD, of Brown UniversitySchool of Medicine, who is also a member of Neoprobe's ScientificAdvisory Board. Four other leading cancer researchers participatedin the symposium.

"This symposium continues our efforts to keep our membersinformed about the latest theories and treatments for colorectalcancer," said Dr. Bland, who was recently elected Presidentof the SSO. "Although the incidence of colorectal cancerin the United States has decreased slightly, it is ranked thirdhighest in causing cancer deaths. Almost half of patients dieof the disease. Surgery is still the most effective treatment.New research and innovative techniques are the best hope for improvingour ability to treat these patients successfully."

Speakers joining Dr. Bland in the symposium panel included IsaiahFidler, 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, whodiscussed "Molecular Mechanisms in Tumor Growth", JohnDaly, MD, New York Hospital, Cornell University Medical Center,who provided a "RIGS Clinical Update," and

Jeffrey Schlom, PhD, National Institutes of Health, National CancerInstitute, who talked about "Future Carriers and CurrentStrategies to Upregulate Antigen Expression."

Results of Pivotal Trials in Metastatic Colorectal Cancer

Dr. Daly's talk included the first announced results of Neoprobe'strials involving metastatic colorectal cancer patients at 24 cancercenters and hospitals in the United States, Europe, and Israel.

The RIGS procedure helped surgeons find additional cancer in oneout of every five evaluable patients (those who had biopsy-provenlocalized tumor and who completed the study). The additional tumorwas confirmed by conventional pathologic tests. Both a CT scanand the surgeon had missed the tumor found by the RIGS system.Using this new information, surgeons changed surgical managementdecisions for most of the patients who had an additional RIGS-locatedtumor. 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 effortto ensure complete removal.

"Optimal treatment for each patient depends on knowing thefull extent of the patient's cancer," Dr. Daly stated. "Whenthe RIGS system gives more information than ordinarily is available,surgeons are able to individualize treatment for those patientsmore accurately."

The results of these pivotal clinical trials, along with thoseof previous studies with the same targeting agent for metastaticcolorectal cancer, are the basis for Neoprobe's marketing applicationsfor the company's first RIGS product. The applications are plannedfor submission in Europe and the United States. Neoprobe is currentlyinvolved in discussions and review of the phase III data withthe FDA.

The company's full analysis of the pivotal trials will be completedupon submission of the marketing applications for RIGScan CR49.These trials are called "pivotal" because they are thelast of a sequence of trials conducted to show the safety andeffectiveness of a drug or biologic.

The RIGS system, a new diagnostic tool for surgeons, works byinjecting a cancer patient before surgery with a low-level radioactive,cancer-specific targeting agent. During the operation, the surgeonuses the RIGS gamma-radiation-detecting probe to locate tissuethat contains a significant amount of the radioactive targetingagent.