SILVER SPRING, Md. _ The FDA's Medical Imaging AdvisoryCommittee Friday easily gave its approval to Immunomedics Inc.'sCEA-Scan to be marketed for use in conjunction with otherdiagnostic tests for bowel cancer.
The scan is expected to enhance patient management by reducing thenumber of unnecessary biopsies and laparotomies, thereby reducingunnecessary health care expenditures and exposure of patients tounnecessary risks. When CEA-Scan was used in conjunction withcomputerized tomography (CT) scans, 97 percent of patients wereconfirmed to have a malignancy at biopsy or surgical explorations.
Immunomedics (NASDAQ:IMMU) closed Friday at $8.50 per share,up 38 cents.
Unnecessary biopsies and laparotomies are significant problems foroncologists who often find that the patient has either no disease orinoperable malignancy. A battery of diagnostic tests has the ability toreduce costs and the risks associated with the invasive procedure. "Ifwe had a better imaging modalities there would be fewer unnecessarysurgeries," said Kevin Hughes, an oncologist at the Hitchcock-LaheyClinic, of Dartmouth University, in Hanover, N.H.
CEA-Scan is a monoclonal antibody fragment of a mouse antibodydirected against the carcinoembryonic antigen (CEA). It is labeledwith technetium-99m, a commonly used, inexpensive radioisotope. Itwas tested by Immunomedics in patients with colorectal cancer.Other Phase II and III trials are underway to assess its applicability inpatients with lung, breast and ovary cancers.
CEA-Scan will be marketed in Western Europe and select EasternEuropean countries through an agreement with Mallinckrodt Medical,B.V., a European operating unit of St. Louis-based MallinckrodtGroup Inc., subject to marketing clearance.
Colorectal cancer cases have been increasing by 138,000 each year,claiming over 48,000 U.S. victims annually, according to thecompany.
"We are delighted with the committee vote. It was virtuallyunanimous," said David Goldenberg, chairman of Morris Plains,N.J.-based Immunomedics, immediately after the vote.
Goldenberg dismissed concerns raised by several members that thatthe CEA-Scan could be used as a screening device instead of as acomplementary diagnostic procedure. "There will be no off labeluse," Goldenberg told BioWorld Today. "It is not a screening test. Itis indicated for patients who have already been diagnosed with canceror in whom the cancer is spreading," he stated.
Committee consultant Ed Sausville, an official with the developmenttherapeutic program of the National Cancer Institute, NationalInstitutes of Health, in Bethesda, Md., raised the concern that CEA-Scan "not be used every three months to check on CEA status or toscreen a person with a family history of cancer."
"CEA-Scan is not a `shotgun" diagnostic test. It will not replace CTscans. There is a discreet context in which it should be used,"commented committee consultant Roger Cohen, professor ofmedicine, at the University of Virginia, in Charlottesville, Va.
The committee voted 12-to-0 that CEA-Scan be approved as aninjectable imaging agent used in conjunction with CT scans toimprove the management of patients already found to have colorectalcancer.
Immunomedics has agreed to develop a clinical practice algorithm toguide its optimal use among clinicians. The algorithm, which will bepart of the labeling, will define the situations in which its use isappropriate. The committee's votes provided advice to the FDA onhow to word this treatment guideline.
The committee voted unanimously on every issue except for onewhich elicited an 11-to-1 response from the members.
In patients for whom surgery is indicated, use of the CEA-Scanwould be appropriate to confirm the presence and location ofresectable disease and to demonstrate additional possible sites ofdisease in the liver and extrahepatic abdomen, the committee agreed.
In patients who are found by CT to have inoperable bowel cancer, theCEA-Scan would be appropriately used to confirm the presence ofinoperability. On this issue one committee member disagreed,producing the only non-unanimous vote.
Late last month Immunomedics reported having $26.4 million in cashand cash equivalents at the end of 1995. n
-- Michele L. Robinson Washington Editor
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