FDA Reviewing New MRI Contrast Agent as Alternative to Gadolinium

The FDA has granted a Fast Track Designation to a new type of MRI contrast agent, ferumoxytol, which could be a safer alternative to gadolinium-based contrast agents for individuals with chronic kidney problems.

Gadolinium MRI contrast agents, which allow the doctor to differentiate blood vessels from nearby tissue, have been linked to a potential risk of nephrogenic systemic fibrosis (NSF) for individuals with moderate to severe kidney problems.

The devastating progressive condition, which is also sometimes referred to as nephrogenic fibrosing dermopathy (NFD), is associated with a hardening and thickening of the skin and connective tissue. The rigid and coarse skin that can form around the joints leads to severe restriction on movement, often requiring use of a wheelchair within weeks of the first symptoms.

There is no cure or consistently successful treatment for NSF, and it often contributes to a premature death. The FDA added a “black box” warning to gadolinium based contrast agents last year, advising doctors to screen patients for impaired renal function before an Enhanced MRI.

The FDA reserves the Fast Track Designation for products that are intended for treatment of serious or adverse conditions or have the potential for use in unmet medical needs. This designation helps to accelerate the process of development and review of these products by allowing more frequent interactions with the FDA and by various other means.

The FDA’s decision to allow a quicker approval process for fermoxytol was mainly driven by the potential for this newer diagnostic agent to serve as a safe alternative for individuals with chronic kidney disease to obtain a Vascular Enhanced (VE) MRI for assessment of peripheral arterial disease. If approved, it could be a life-saving alternative to the gadolinium-based contrast agent for individuals with advanced kidney disease.

Ferumoxytol is manufactured by AMAG Pharmaceuticals. The firm’s President and Chief Executive, Brian J.G. Pereira, said in a statement, “We plan to initiate a Phase II study of Ferumoxytol for VE-MRI for the detection of clinically significant arterial stenosis or occlusion in subjects with intermittent claudication (leg pain with walking) in the third quarter of 2008”.

AMAG Pharmaceuticals anticipates FDA action on its new drug application (NDA) in the second half of October 2008.