At the North American Spine Society Annual Meeting, in a Sept. 25 panel session titled "BMP in 2019 – The Biologic Hasn't Changed but the Evidence Has," a group of physicians discussed the state of BMP today.
The panel included Eugene Carragee, MD, Wellington Hsu, MD, Greg Schroder, MD, Chris Chaput, MD, and Peter Whang, MD. The panel was moderated by Harry Smith, MD. BMP was initially developed for hard-to-fuse patients, including those that needed multilevel procedures and had other comorbidities. But after further development, Medtronic brought BMP to the market as a device: Infuse.
Infuse received initial FDA clearance for single-level ALIF procedures in 2002 and the clinical trials revealed positive results with few adverse events. However, BMP came under scrutiny as surgeons began experiencing complications and publishing peer review articles based on their findings.
The Yale Open Data Access Project launched in 2011 to examine the original data from the industry-sponsored studies. The project represented a new model for evaluating industry-sponsored clinical trials to foster public trust while minimizing risk and maximizing benefit to patients. Medtronic supported the project with a $2.5 million grant and provided all data for independent review.
Dr. Whang reviewed the original YODA studies, which were published in the Annals of Internal Medicine in 2013. He outlined the findings in these studies, examining the potential for increased adverse events and cancer risk.
"In summary, there could be potentially some benefits in terms of fusion rate and disability for Infuse versus iliac crest bone graft," said Dr. Whang "In terms of safety, there are some concerns with early back and leg pain, potential for cancer risk, although it was less apparent after two years, but the overall adverse events and specific adverse event risks were not significantly different."
Dr. Schroder discussed the data post-YODA. Since then, there have been 650 different studies published examining BMP, including 80 in 2019 so far. He pointed specifically to a prospective randomized trial from Canada, including 197 patients at eight centers found BMP had an increased rate of fusion compared to those with iliac crest fusion. However, there was no difference on health-related quality of life outcomes at two and four years. He concluded that the post-YODA data didn't show evidence that BMP caused cancer.
Dr. Hsu talked about BMP use today, outlining the "hype curve" history of initial rapid adoption, steep utilization drop, and then steady growth again in BMP use. "We have seen the evidence to show that perhaps the complications that we were exposed to, was really because we were over-zealous in use and perhaps not as much from the actual product," he said. He argued it's more reasonable for surgeons to adopt technology more judiciously in the future.
There are two clinical trials examining Infuse today, sponsored by Medtronic. The first is a posterolateral fusions trial first posted in 2017 with an expected completion date of next year. The second trial is for transforaminal lumbar interbody fusion procedures. The company plans to recruit up to 1,000 patients to participate at around 50 sites in the TLIF study.
Dr. Hsu went on to report that in 2011, BMP revenue was around $900 million and then dropped to $504 million at its nadir; since then, BMP revenue has had an average annual growth rate of 7.5 percent. In 2010, growth factors comprised almost 50 percent of the bone grafts that were used, but this was cut in half over the following five years as new articles were published, reported Dr. Hsu.
"I think after the next four, five, six or seven years, we will see growth in the use of growth factors as more evidence comes out," Dr. Hsu said.
In a statement, Medtronic praised the discussion of BMP and Infuse at the meeting and went on to state: "Medtronic believes in the safety and effectiveness of Infuse for approved indications. We're committed to advancing the evidence of Infuse to support physicians as they make decisions about treatment options. In addition, we're committed to offering a broad range of bone graft technologies to help physicians address a spectrum of patient needs."