* Most on panel see more risk for GE, Covidien drugs
* FDA official: Panel tilted toward stronger warning
* GE says higher risk for any MRI drugs unproven
GAITHERSBURG, Md., Dec 8 (Reuters) - MRI imaging drugs from GE Healthcare (GE.N) and Covidien COV.N appear linked to a higher risk of a potentially fatal skin disease for some patients than similar products, most members of a U.S. advisory panel said on Tuesday.
A majority of the Food and Drug Administration panel felt current data showed GE's Omniscan and Covidien's Optimark were associated with a higher risk of nephrogenic systemic fibrosis (NSF) for patients with severe kidney disease, panel chairman Robert Harrington said. NSF causes thickening of the skin and organs.
Most panelists also felt prescribing instructions for those two drugs should clearly warn they should not be used in severe kidney disease patients, an FDA official said.
While opinions on that point were mixed, the "preponderance of opinion" favored that type of warning, which Covidien already voluntarily added to Optimark, Dr. Dwaine Rieves, the FDA's head of medical imaging and hematology products, told reporters.
The panel agreed the risk applies only to patients with severe kidney disease, which Covidien estimates affects less than 0.5 percent of the U.S. population.
The FDA will consider the advisers' input. The agency did not ask the panel to formally vote on whether to recommend any new warnings.
The products have been given to millions of patients to help make MRI scans easier to read.
GE, Bayer (BAYGn.DE) and Covidien are facing lawsuits from people who say they were harmed by the products.
All of the drugs in the family known as gadolinium-based contrast agents (GBCAs) already carry a strong "black box" warning advising doctors to avoid the drugs in severe kidney disease, unless a doctor decides the diagnostic information is essential and unavailable otherwise.
Leaving the same warning on all the drugs "may cause more problems than if you distinguish between the drugs as best as you can," even though "we all agree it's not perfect data," said consumer advocate Dr. Sidney Wolfe, a panel member and head of Public Citizen's Health Research Group.
The FDA has received hundreds of reports of NSF in patients injected with the products, most with Omniscan and Bayer's product, Magnevist, the most widely used of the group with 2008 sales of about $354 million,
Manufacturers and FDA reviewers said reports of NSF had dropped dramatically since the 2007, which led some panelists to urge the agency to stick with that approach.
"We already have a black box warning that as far as we can see has taken care of the problem," said panel member Dr. Lawrence Hunsicker, a kidney specialist at the University of Iowa Hospitals and Clinics.
Some panelists said Magnevist should be included in the higher risk group, but Harrington said there was "less consensus" on that drug.
NSF triggers thickening of the skin, organs and other tissues that makes it difficult to move and can lead to broken bones, although the exact cause is unclear. There is no effective treatment and it can be fatal.
Dr. Eric Cantor, head of medical professional services for GE Healthcare, told the panel the idea that some GBCAs have a higher NSF risk than others "remains unproven" and labeling them differently could create "a misperception of one agent being inherently safer than another."
GE, in a statement after the meeting, said it would "actively cooperate with the FDA to determine the best path forward." Omniscan's global sales were $80 million in 2008.
Covidien, in a statement, said Optimark "has an excellent risk/benefit profile" when used as directed.
Bayer said in a statement the topics the panel debated were "complex" and the company would continue to work with regulators to address the NSF issue.
Competing drugs include Bracco Diagostics' Prohance and Multihance, which FDA reviewers said appeared linked to the lowest NSF risk. It is too soon to tell the risk with two other recently approved products, Bayer's Eovist and Lantheus Medical Imaging's Ablavar, FDA staff said. (Reporting by Lisa Richwine; Editing by Steve Orlofsky)