American Biogenetic Sciences Inc. (ABS) announced Friday thatit has received clearance from the FDA to begin clinical testingof its fibrin-specific monoclonal antibody for imaging bloodclots in the lungs and heart.

The Notre Dame, Ind., company (NASDAQ:MABXA) submittedits investigational new drug (IND) application to the FDA forthis product exactly one year ago, in March 1992.

This is a fairly lengthy delay by the FDA. The agency approvedthe Phase I protocol for Centocor Inc.'s Fibriscint (anotherimaging agent for blood clots), for instance, in a matter ofmonths.

"Clearly, it's not good news that it took so long," said JimMcCamant, editor of the Medical Technology Stock Letter.

Leonard Suroff, ABS's corporate counsel, told BioWorld that thedelay was due to the "usual procedures" one might encounterwhen interacting with the agency. "FDA did have certainquestions (about the protocol), to which the companyresponded," Suroff said.

The product, MH-1, is a monoclonal antibody fragment specificto the fibrin component of a blood clot. ABS has labeled itsagent with the radioactive isotope technitium-99m. Animalstudies have shown that MH-1 can pinpoint the location ofblood clots in the lungs and heart within 30 minutes ofinjection.

Currently, only invasive procedures, including pulmonaryangiography and contrast venography, are available to detectclots in heart and lung. With the market for blood clot imagingagents projected at $1 billion or more, it's not surprising thatABS has competitors.

Centocor (NASDAQ:CNTO) of Malvern, Pa., for example, filed itsPLA on Fibriscint, another murine monoclonal linked totechnitium that targets fibrin, in Dec. '91.

Bio-Technology General Corp. (NASDAQ:BTGC) has beendeveloping a fibronectin fragment -- the fibrin binding domain(FBD) -- to be tagged with technitium-99m to detect clots in thelungs and veins. BTGC has already taken this agent throughpilot clinical studies, but tagged with a different imagingisotope.

"The initial information indicates that the agent was verysuccessful in identifying clots," said Leah Berkovits,administration manager for the New York company. She addedthat BTGC is now "adapting" the compound to technitium-99m."We hope to proceed with further clinical studies this year,"Berkovits told BioWorld.

And before Cytogen Corp. (NASDAQ:CYTO) decided to focus itsbusiness on cancer diagnostics and therapeutics, the Princeton,N.J., company was developing the imaging agent Thromboscan,a small chain of amino acids linked to technitium that targetsthe fibrinogen receptor on platelets. Cytogen finished its PhaseI studies on Thromboscan, which provided "proof of principal,"according to Mary Beales, director of corporatecommunications, but is doing "no further development work"on the product at this point, Beales said.

Meanwhile, Applied Biogenetic is just starting its foray intohuman clinical trials; Phase Is on MH-1 are scheduled at TheJohns Hopkins University School of Medicine in Baltimore andWest Haven VA Medical Center in West Haven, Conn.

-- Jennifer Van Brunt Senior Editor

(c) 1997 American Health Consultants. All rights reserved.