The past several years have raised serious questions about the safety of Medtronic Inc.’s Infuse bone growth product. According to a report from MedCityNews.com, some doctors have already limited their use of Infuse because of concerns that it might cause cancer and other serious complications, and it seems doubtful that this course can be reversed.
Infuse is made from a genetically engineered material called rhBMP-2 (recombinant human Bone Morphogenetic Protein-2), which stimulates bone growth. First approved by the U.S. Food and Drug Administration (FDA) in 2002, it has been cleared for use in a type of spine surgery called anterior approach lumbar fusion, as well as two types of dental procedures. However, it’s long been recognized that Infuse is frequently used in procedures not approved by the FDA. In 2008, the agency warned that Infuse and similar rhBMP-2 products had caused serious problems when they were used off-label in cervical spine (neck) surgeries.
For several years now, Infuse has been at the center of controversy. Most recently, Dr. Eugene Carragee presented a study at the North American Spine Society that raised serious questions about a possible association between rhBMP-2 and an increased risk of cancer. Carragee’s analysis of a Medtronic study for its Amplify product, a higher-dose version of rhBMP-2, found that the study failed to identify a significant cancer risk though both the research team and Medtronic were aware of data linking the product to cancer. Medtronic has not been able to convince the FDA to approve Amplify. But, the findings have important implications for Infuse, as doctors often administer it at levels significantly above the recommended dosages, ones that approach or exceed the amount of rhBMP-2 found in a dose of Amplify, when they use Infuse in off-label procedures, Carragee said.
Carragee, a prominent researcher and spinal surgeon with Stanford University, also serves as editor of The Spine Journal. Over the summer, he published an article in that journal asserting 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
These controversies have caused Infuse sales to decline, as doctors began limiting its use or abandoning it altogether.
“Someone who is a very poor healer, someone who is in a revisional surgery, someone who is older and not in child-bearing age … some doctors still see an (Infuse) application in treating these hard -to-treat people,” Caroline Corner, an analyst with investment bank MLV & Co, told MedCityNews.com. “But doctors in general are definitely shying away from using Infuse (most of the time).”
In an effort to salvage the reputation of Infuse, Medtronic has commissioned Yale University to oversee two independent, systematic reviews of all Infuse-related clinical data, the results of which are expected to be concluded in the next fiscal year. But even if the Yale reviews provide full vindication of Infuse, Corner told MedCityNews.com that it’s unlikely that sales of the product will fully recover.
“Given that we’ve already had the proverbial eyebrow raised about Infuse, will they (doctors) go back to it, I don’t think so,” she said.