FDA: Proposed Acusphere contrast agent too risky for approval
Imagify might never come to market in the U.S. Image Source: EH Online  
Federal regulators announced Monday that the safety risks associated with Acusphere’s ultrasound heart-imaging agent, Imagify, are inappropriate for the product's proposed clinical use.

Acusphere is seeking FDA approval for Imagify (Perflubutane Polymer Microspheres) for Injectable Suspension to help identify blood-flow problems in patients with stable chest pain.

Clinical studies with Acusphere suggest Imagify may result in acute inflammation and abnormally low blood pressure, according to FDA briefing documents posted Monday. The agency said that 17 patients who were administered Imagify during clinical studies experienced adverse events that were serious enough to cause them to permanently stop taking the product. Such adverse events include vertigo and hypertension.

The Watertown, Mass.-based Acusphere acknowledged that Imagify can decrease blood pressure, and said that other problems were mild in intensity and reversible.

The FDA also noted that Imagify's performance is not sufficient for the proposed diagnostic use of the product. The agency released its briefing information ahead of this Wednesday’s Cardio Renal Advisory Committee Meeting, where the panel will be asked to review and discuss the new drug application for Imagify.

In October 2007, the FDA placed a black-box warning on other ultrasound heart-imaging agents, after receiving post-marketing reports that associated several of the products with hundreds of adverse events, including more than a dozen deaths. The reports were associated with GE Healthcare's Optison and Lantheus Medical Imaging's Definity.