The Spine Journal has dedicated its June issue to a series of papers that carefully reject previous research supporting the use of Infuse, a controversial, but popular bone growth product commonly used in spinal fusion surgeries.
Infuse is used in a quarter of the estimated 432,000 spinal fusions performed in the U.S. each year. In a new study in The Spine Journal experts assert that the data backing Infuse's widespread use were published by researchers who received large sums of money from its maker, Medtronic, and who exaggerated the product's benefits while concealing its risks. Fifteen of the surgeons got at least $62 million from the company over the past decade, the paper said, citing an analysis of Medtronic documents and disclosures on the company's website.
The purported side effects, they said, include male sterility, infection, bone loss and unwanted bone growth. A stronger version of Infuse, called Amplify, was recently rejected for approval by the FDA because of concerns about possible cancer risks
In the past year, Medtronic has made $900 million from Infuse. The median amount of money paid out by Medtronic over time to researchers involved in some of the previous studies ranged from $12 million to $16 million, according to The Spine Journal — and most of that money went to a few people.
“The history of [Infuse] research is a cautionary tale for all medical professionals, researchers and patients,” said Dr. Christopher M. Bono of Brigham and Women's Hospital in Boston and acting editor-in-chief of the June issue of The Spine Journal. “As this matter demonstrates, the spine care field is currently at a precarious intersection of professionalism, morality and public safety.”
“I'm not a mind reader for why these researchers did what they did. But there appears to have been a systematic bias in those papers,” said Dr. Eugene Carragee, director of Stanford's Orthopaedic Spine Center and lead author of the new study. “I don't think there was anything completely unique about this circumstance. This study highlights a basic flaw of the system.” Carragee and his co-authors are among the first to publicly, and aggressively, challenge their peers on whether such financial relationships bias researchers.
Medtronic's CEO, Omar Ishrak, noted that the Spine Journal articles did not question the data that the company originally submitted to the FDA for approval of Infuse in 2002. A U.S. Senate committee is investigating whether surgeons who were paid consulting and other fees by Medtronic failed to note the complications of Infuse. The company last week said the three main side effect concerns raised by the committee are listed as warnings on the product labels, as approved by the U.S. Food and Drug Administration. Ishrak said, “Based on that data, we strongly believe that the safety profile reported to the FDA and summarized in the product label support the safe use of rhBMP-2 for the identified indications.” The company will continue to investigate questions surrounding researchers' potential conflicts of interest and refine policies as needed, he said.