- Bayer's Gadavist contrast agent has been greenlighted by the FDA for diagnosing coronary artery disease, becoming the first to be approved by the agency for use in cardiac magnetic resonance imaging (MRI), the company said Monday.
- The approval was based on demonstrated effectiveness in two multinational Phase III studies of about 1,000 adults with suspected or known coronary artery disease, the most common form of heart disease.
- Contrast agents are injected into a vein to improve visualization of internal organs, blood vessels and tissues during an MRI to aid in diagnosing medical conditions.
The approval of Gadavist for diagnosing coronary artery disease is the fourth indication for the gadolinium-based contrast agent. FDA first approved Gadavist in 2011 for intravenous use in MRI to detect and visualize areas with disrupted blood brain barrier or abnormal vascularity of the central nervous system in adults and children two years of age and older.
In 2014, the contrast agent gained expanded approval to assess the presence and extent of malignant breast disease in adults. It also received an indication for use in evaluating the central nervous system of pediatric patients under two years old. Two years later, Gadavist was approved for use with magnetic resonance angiography to assess supra-aortic or renal disease in adult and pediatric patients.
Gadolinium is a heavy metal. Gadolinium-based contrast agents for use in MRI were the subject of a 2017 FDA safety communication alerting patients and healthcare professionals about retention of the drug in the body, including the brain, for months to years after a patient receives the injection. Although the drug is mostly eliminated from the body through the kidneys, trace amounts may remain long term.
Bayer warns that gadolinium-based contrast agents increase the risk of nephrogenic systemic fibrosis (NSF) in patients with impaired ability to eliminate the drugs. The risk appears highest among patients with chronic severe kidney disease and acute kidney injury, meaning the gadolinium-based agents should not be used in these patients. NSF can cause fatal or debilitating fibrosis affecting the skin, muscles and internal organs.
In the safety communication, FDA said it concluded the benefits of all approved gadolinium-based contrast agents outweigh any potential risks. In addition to Gadavist, the agency listed seven other approved gadolinium-based agents, and noted some have been on the market for more than a decade.
FDA advised doctors to consider the retention characteristics of each drug when choosing a contrast agent for higher-risk patients such as those requiring multiple lifetime doses, pregnant women, children and those with inflammatory conditions. Minimizing repeat imaging studies using the agent was advised. In addition, manufacturers were required to conduct additional studies to further assess the safety of the agents.