After ending marketing and distribution deals with Mallinckrodt Inc., Immunomedics Inc. said it will take over marketing CEA-Scan, its imaging test for colon cancer, in the U.S. and Europe.

The decision to terminate agreements with Mallinckrodt, of St. Louis, was strategic and not based on dissatisfaction with its efforts, said Kevin Brophy, vice president and chief financial officer of Morris Plains, N.J.-based Immunomedics.

Since July of last year, Immunomedics has been assembling its own sales and marketing force to provide education and training in the proper use of CEA-Scan, Brophy said.

"We have 16 or 17 sales reps plus technical support, dealing directly with nuclear medicine people," he said. "We're building that organization [in the U.S.], and we're doing the same thing in Europe."

The test is "not difficult to use, but there are parameters," Brophy added. "It involves mixing a radioactive isotope with the injected product."

Approved by the FDA in 1996, CEA-Scan is an in vivo imaging agent composed of a monoclonal antibody fragment labeled with technetium-99m for detection of the carcinoembryonic antigen (CEA), which is expressed by colorectal cancer cells and by many other tumor cells. (See BioWorld Today, July 2, 1996, p. 1.)

Distribution of CEA-Scan in Europe will be handled by Indianapolis-based Eli Lilly and Co., which also distributes LeukoScan, Immunomedics' test that detects bone infection, in Europe.

Talks with a pharmaceutical distributor to handle CEA-Scan in the U.S. are under way, Brophy said.

The marketing and distribution arrangements with Mallinckrodt were made in 1995 and 1996, respectively. Immunomedics' stock (NASDAQ:IMMU) closed Wednesday at $4.375, down $0.438. — Randall Osborne