Staff Writer

Alliance Pharmaceutical Corp. received FDA approval for its ultrasound imaging agent, Imagent, developed to provide anatomical information about the heart not obtainable using echocardiography alone.

Formerly known as Imavist, Imagent was approved for patients with suboptimal echocardiograms to opacify the left ventricle, improving visualization of the heart's main pumping chamber and bettering delineation of its endocardial borders. San Diego-based Alliance said Imagent (perflexane lipid microspheres) improves the clarity of echocardiograms when used in conjunction with ultrasound imaging by enhancing the contrast between different types of tissues.

"Several of the major ultrasound equipment manufacturers have new software on their equipment that is to be used specifically with a contrast agent such as Imagent," said Gwen Rosenberg, Alliance's vice president for corporate communications. "The equipment and the ultrasound contrast agents have evolved on the same timeline. So now you have a synergy where there's equipment that is to be used with a specific agent, and an agent that works best with the new software and equipment."

Packaged as a dry powder and stored at room temperature, Imagent is reconstituted with water to form an osmotically stabilized suspension of microscopic spheres containing a perfluorochemical (perflexane) vapor and physiologic gases. Imagent is then injected intravenously into a patient undergoing a cardiac ultrasound exam.

The approval was based on an analysis of a multicenter, 410-patient Phase III study.

"The data showed that Imagent improved both the endocardial border delineation and the accuracy of assessment of segmental wall motion," Rosenberg said.

While Imagent has no known contraindications, the company advised that it should be administered cautiously in patients with cardiac shunts or severe pulmonary vascular disease. Alliance likened the overall incidence of adverse events to that of placebo (saline), with such events including headache, hypertension and nausea.

Adverse events were a source of concern with another Alliance product early last year.

The company's Oxygent (perflubron emulsion) product hit a snag, as Alliance halted enrollment in its Phase III cardiac study with Oxygent due to an imbalance in adverse events, particularly the incidence of stroke. Two months later, though, Alliance released preliminary data showing that no evidence directly linked Oxygent to the adverse events. It attributed the problem to the procedure, not the drug. (See BioWorld Today, Jan. 10, 2001.)

Oxygent, an intravenous oxygen carrier, is being developed in the U.S., Canada and Europe in conjunction with Deerfield, Ill.-based Baxter Healthcare Corp.

"We are preparing to start an international Phase III study," Rosenberg said, "and we expect that to start around mid-year."

The product will be tested in patients undergoing general surgery procedures, with a control group receiving blood and the treatment group receiving Oxygent, with a goal of showing that Oxygent reduces the amount of donor blood needed during a procedure.

Alliance suffered another setback a year ago, when preliminary data of a Phase II/III adult ARDS study showed that partial liquid ventilation with LiquiVent (perflubron) failed to meet its primary or secondary endpoints, which sought improvement in ventilator-free days and 28-day mortality. (See BioWorld Today, May 23, 2001.)

But Imagent is moving forward. It will be introduced at next week's meeting of the American Society of Echocardiography in Orlando, the same venue in which its Phase III trial data will be presented.

"This is a market that is expected to grow as physicians learn about the value of ultrasound contrast," Rosenberg said.

Two competing ultrasound contrast agent products, Optison and Definity, have not been aggressively marketed, she said.

"Imagent is coming out at a time that on one hand, we have a certain degree of knowledge in the cardiology community about what ultrasound agents can do," Rosenberg said. "But because there has not been a lot of effort on behalf of [marketing] these products, I think we're in a very good position to introduce Imagent."

Alliance will market the product in partnership with Cardinal Health Inc., of Dublin, Ohio, and Columbus, Ohio-based inChord Communications Inc., an independent health care communications company.

Alliance is the first company to participate in Rxpedite, a partnership between Cardinal and inChord that provides sales and marketing services. Cardinal will hire, train and deploy a dedicated Alliance sales force and ultrasound medical liaison specialist team. Cardinal also is extending to Alliance a revolving line of an undisclosed amount of credit, which will be repaid from product revenues.

Specific terms of the marketing partnership were not disclosed. Alliance's European partner for Imagent is Berlin-based Schering AG.

Alliance's stock (NASDAQ:ALLP) gained 25 cents Monday to close at $2.15.