Medtronic Infuse Associated with Higher Rate of Cancers than First Believed, Researcher ClaimsNov 4, 2011 | Parker Waichman LLP
Dr. Eugene Carragee, a Stanford University School of Medicine professor and editor of The Spine Journal. has raised more questions about Medtronic Inc.'s Infuse bone growth product. According to Carragee, Infuse may be more strongly associated with cancer than previously thought.
In June, a Spine Journal article authored by Carragee reported that Medtronic-paid surgeons had failed to report serious complications from Infuse, including cancer, sterility in men, infections, bone dissolution and worsened back and leg pain. The article said complications occurred in 10 to 50 percent of patients who got the product in 13 Medtronic-funded clinical trials between 2000 and 2010.
Yesterday, during a presentation at North American Spine Society meeting in Chicago on Thursday, Carragee said a new analysis he performed of another Medtronic clinical trial raised serious concerns about a cancer risk posed by rhBMP-2, the bone growth protein found in Infuse. According to Carragee, his analysis of a Medtronic-funded study that involved 239 patients who got the company's Amplify product and 224 who got a conventional graft of their own hip bone indicated a strong connection between the protein and cancer. At roughly three-year follow-up, 5% of those who got Amplify were diagnosed with a new cancer, compared with 1.3% who got the hip bone graft. After two to three years of follow-up, Amplify patients were four to five times more likely to develop at least one new malignancy.
Like Infuse, Amplify is made with rhBMP-2, but at higher dose. In March, the U.S. Food & Drug Administration (FDA) declined to approve Amplify because of cancer concerns. However, when the Amplify study analyzed by Carragee was published in 2009, the text never mentioned the cancer cases, and they were only noted in an accompanying table. The authors - who had received millions in royalties for other Medtronic products - claimed they weren't statistically significant, something Carragee disputes. By his reckoning, patients who received rhBMP-2 were three to five times more likely to develop cancer within a few years of implantation.
In an interview with The New York Times, Carragee said the cancer findings could have serious implications for people receiving Infuse. Doctors often administered Infuse off-label at levels significantly above the recommended dosages, ones that approach or exceed the amount of rhBMP-2 found in a dose of Amplify, he said. Carragee also voiced particular concern about the use of Infuse in certain patients like smokers or those with genetic factors that put them at higher risk for cancer, the Times said.