MRI opportunities lure Mallinckrodt

Mallinckrodt Medical has jumped into the MRI contrast agent businesswith a patent in one hand and a license to market in the other.The company is also on the verge of clinical trials of an extracellular,nonionic gadolinium agent for MR studies.

The patent relates to a method of formulating MR contrast andis intended to provide an extra margin of safety, according toDr. Gene Fox, senior vice president for science and technology.It stems from work conducted by Mallinckrodt in the early 1980s.

"With gadolinium agents there is always the possibilitythat some of the free gadolinium could come off the molecule,"he said. "Anyone who uses these agents has to have excessligands around to tie up any that become free and potentiallytoxic. And so we patented that."

The patent was issued in January.

"I think everyone who understands what is involved withgadolinium is using excess ligands," Fox said. "Butwe came to that understanding earlier than anyone else. The patentgives us coverage on the use of excess ligands in products."

The patent formulation is already being used in the gadoliniumagent, said Dr. Max Adams, director of radiology and cardiologyR&D. Mallinckrodt expects to have the agent in clinical trialsshortly.

The company has also licensed Advanced Magnetics' bowel markeragent, AMI-121 (SCAN 8/1/90). A new drug application has beenfiled with the Food and Drug Administration, Adams said.

"That's in the hands of the FDA, and it will probablybe a few years before it is approved," he added.

Mallinckrodt is making a "major effort" in the MRIcontrast arena because of the multiple opportunities the modalityrepresents, he said.

"We see MRI contrast as an important research area forus as an imaging company," he said. "Down the road we'llbe looking at better agents, organ-specific agents, and workingin a variety of chemical areas."