Infuse, used in spine surgery, has been linked to complications that include sterility in men.
Two prominent U.S. senators have asked Medtronic Inc. for more information about the financial relationships between the medical technology company and doctors conducting clinical trials on a controversial spine surgery product.
A letter that the senators sent Tuesday also requests information about post-surgery complications associated with the bone-growth product, called Infuse. The product, which fuses bone in back surgery, has been linked to complications in some patients, including sterility in men, excessive bone growth in areas beyond the spine, and leg pain. Other concerns have been raised about a potential link between Infuse and cancer, a charge the company disputes.
Sent on behalf of the Senate Finance Committee, the letter was addressed to Medtronic's new chairman and CEO, Omar Ishrak, who joined the Fridley-based company last week. It was signed by committee members Charles Grassley, R-Iowa, and Max Baucus, D-Montana.
The senators express concern about suggestions raised in press reports that doctors conducting clinical trials examining Infuse's safety and effectiveness may have been aware of the complications "but failed to report this in the medical literature."
This issue is compounded by the fact that some of the doctors conducting the studies "have substantial financial ties to Medtronic," the letter states.
The letter notes that one of the authors of an early study testing Infuse's safety and effectiveness, Dr. Thomas Zdeblick of the University of Wisconsin, received more than $23 million in royalty payments from Medtronic since 2002.
Medtronic spokeswoman Mary Beth Thorsgaard confirmed receipt of the Finance Committee's letter and said the company will respond to the request. The letter sets July 11 as a deadline for a response.
Thorsgaard noted that complications cited in the letter are listed on the product's warning label. In regard to cancer concerns, she said 44 clinical trials involving Infuse observed cancer rates that were not statistically different between the patients treated with the product and those who were not.
The senators request a raft of documents, including communications involving post-surgical complications related to Infuse between the company and medical journals, clinical investigators, the Food and Drug Administration, and physician consultants. It also asks for a "detailed account" of payments between the company and Infuse's clinical investigators.
This isn't the first time Grassley has investigated Medtronic's financial ties with its doctor consultants. He has previously probed the relationship between Medtronic and Dr. David Polly, a spine surgeon at the University of Minnesota who is a Medtronic consultant. Documents unearthed in that investigation found that Medtronic paid Polly $1.2 million between 2003 through 2007 for consulting, expenses and honoraria.
Last year, Grassley sent a letter to the company, as well as the head of the U.S. Department of Veterans Affairs, asking for more information about a high-ranking official at the VA who was once a consultant for the company.
Janet Moore • 612-673-7752