By Lisa Seachrist

Washington Editor

WASHINGTON — The FDA granted Molecular Biosystems Inc. (MBI) clearance to market its diagnostic contrast agent, Optison, to enhance cardiac images generated by ultrasound.

In winning approval the last day of 1997, MBI, of San Diego, and its marketing partner Mallinckrodt Inc., of St. Louis, beat out several competitors who had turned to the courts to delay Optison's entrance into the market.

"Even though we were delayed, we were still able to achieve market approval before our competitors," said Gerard Wills, chief financial officer at MBI. "We are very excited by the approval and are hoping to take advantage of the opportunity to be first on the market."

Optison is a perfluorocarbon containing product that enhances ultrasound images by introducing gas-filled microspheres into the blood and allowing physicians to distinguish blood from anatomical structures such as the ventricular heart wall. The FDA specifically approved Optison for use in patients with suboptimal echocardiograms to opacify the left ventricle and to improve the delineation of the left ventricular endocardial borders.

Several other companies have similar perfluorocarbon products in development. The competition between the companies lead to a legal challenge of the FDA's review policies that resulted in the agency deciding in July 1997 that all ultrasound contrast agents would be considered drugs, not devices.

The challenge delayed Optison's approval because it had been reviewed as a device and received a recommendation for approval from the Radiological Devices Advisory Committee on Feb. 24, 1997. As a result, the Center for Drug Evaluation and Research took over the review of Optison.

"We are excited to be in the field of cardiac ultrasound enhancement," Wills said. "It makes ultrasound a stronger tool in cases of suspected heart disease and is an important market as illustrated by the number of companies working on such products."

Wills said Mallinckrodt delivered the first shipments of Optison Jan. 2 and sales are continuing. *