There have been many stories this week on this review in The Spine Journal, which found that a commonly used spinal fusion product is associated with potentially serious complications not previously reported in industry-sponsored studies. Eugene Carragee, MD, the journal's editor-in-chief and professor of orthopedic surgery at Stanford, said he believes there has been some misleading or inaccurate material carried in these stories about the product, known as rhBMP-2 and marketed as Infuse by its manufacturer, Medtronic, Inc.
For instance, the company's CEO said in a statement that the review and related articles in the journal "do not raise questions about the data Medtronic submitted to the FDA in the approval process." However, Carragee notes that while the company did report complications to the FDA, the trial design used by Medtronic for the FDA studies were, based on fundamental design flaws, biased in favor of the company's products.
"Therefore we strongly disagree with the Medtronic CEO statements that our report finds the data submitted to the FDA to be reliable. We do not. The data in itself, especially in the high-dose Amplify trial, has been pretty soundly discredited by multiple studies," Carragee said. Several of those studies challenging the FDA study design and biases were published in the same issue of The Spine Journal.
Amplify is the newer version of the product, which has been found to carry a possible increased risk of cancer. It has yet to be approved by the FDA in part because of this concern; however this serious association was not discussed in published studies sponsored by the company.
Carragee also takes issue with a position held by a University of Wisconsin orthopedist who was involved in some of the industry-sponsored studies. The researcher, Thomas Zdeblick, MD, received as much as $23 million from Medtronic, much of it in royalties for the only device tested and approved by the FDA for use with rhBMP-2, Carragee said. Zdeblick has defended himself, telling the New York Times that he did not have a "direct financial interest in the success of Infuse or Medtronic." However, Carragee calls the conflict-of-interest by Zdeblick and some other physicians involved in the trials "as strong as I have seen in medicine in 30 years.
"Although he holds what can be considered a type of monopoly for on-label use, he repeatedly claims he has absolutely no financial interest in BMP-2," Carragee said. "This claim is hardly credible, almost ridiculous."
In a letter to the journal, Zdeblick also claimed that Carragee was absent for 18 months on military duty, during the time of a clinical trial at Stanford that showed the incidence of male sterility associated with the product was about 7 percent, far greater than industry-sponsored studies reported. Carragee said he was at Stanford during the entire trial period of 2002 to 2004 and didn't return to active duty until 2005, so Zdeblick's statement is "pure fabrication." "We are astonished that Dr. Zdeblick would falsely manipulate an Army officer's wartime service record in this manner," the journal editors responded.
Previously: Stanford-led study on Medtronic bone product dominates the headlines, Stanford orthopedist reveals problems with Medtronic spinal fusion product, and Stanford study links spine product to male infertility