BETHESDA, MD 28 October 2011—Lantheus Medical Imaging of North Billerica, Massachusetts, recently announced the removal of some information from the boxed warning for perflutren lipid microsphere injectable suspension, or Definity, and the clarification of other information in the ultrasound contrast agent`s labeling.
The revised labeling (PDF), approved October 24, no longer states that vital signs, oxygen saturation, and electrocardiographic status should be monitored for 30 minutes after the imaging agent is administered to patients with pulmonary hypertension or unstable cardiopulmonary conditions.
Instead, the boxed warning now states that serious and fatal cardiopulmonary reactions have occurred during or after the administration of the drug but are uncommon. Most serious reactions occur within the first 30 minutes after administration, according to the revised boxed warning.
Also removed from the labeling is a statement that the safety and efficacy of the drug in conjunction with pharmacologic or exercise stress testing have not been established.
Definity is indicated as an ultrasound contrast agent to improve the visualization of the left ventricular chamber and endocardial border in patients with suboptimal echocardiograms. The imaging agent was approved in 2001.
The International Contrast Ultrasound Society on October 3 filed a citizen petition with FDA asking the agency to remove boxed warnings from ultrasound imaging agents. According to the petition, research findings that were not available in 2007, when the boxed warnings were added, show that the contrast agents have a favorable "cost-benefit ratio."
During a meeting this past May, FDA advisers expressed a variety of views on the boxed warnings and did not reach consensus on whether to remove them.
GE Healthcare has not announced any labeling changes to the company`s Optison brand perflutren protein-type A microspheres injectable suspension. Optison was named along with Definity in the citizen petition and was also reviewed during the FDA advisers` meeting.