
The Food & Drug Administration wants more answers about possibly elevated cancer risks from Medtronic Inc.’s (NYSE:MDT) Amplify spinal implant, which uses a bone morphogenic protein to stimulate bone growth.
The federal watchdog agency will ask its Orthopaedic and Rehabilitation Devices panel July 27 whether the higher number of cancer cases among patients treated with the Fridley, Minn.-based medical device monolith’s device warrant further investigation. The device uses recombinant bone morphogenetic protein-2 to promote bone growth at the site of the implant, which is designed to treat vertebral compression in the lower back in patients with degenerative disc disease.
Of the patients implanted with the device in clinical studies, nine developed cancer over a two-year span (3.8 percent of that group), compared with two, or 0.9 percent, in the control group, according to the FDA (PDF). Over a five-year span, there were 13 cancer events in 12 patients in the Amplify group (5 percent), compared with four cases in four patients (1.8 percent) in the control group. Two more Amplify cancer events were reported in Medtronic’s 2010 annual report for its investigational device exemption, with one more in the control group, bringing the total number of cancer events to 15 for 12 Amplify patients and five events for five of the control group patients.
Although none of the cancer events was classified as related to the device, the FDA wants the panel to "discuss the clinical significance of the results of these evaluations of the reported cancer events, and discuss whether any additional evaluations or analyses are necessary," according to the agency.
"Specifically, does the Panel believe that there is a clinically and/or statistically significant rate of incidence of overall cancer events in patients treated with Amplify and/or rhBMP-2 in general, as compared to the control group and expected rates in the general population?" according to an agency summary. "Has the sponsor provided adequate safety data to definitively address the issue of cancer, or are additional evaluations or analyses necessary? In addition, the FDA would like the Panel to discuss the impact on the determination of reasonable assurance that the proposed device is safe for the specified indications and intended patient population and whether any additional data or analyses are needed."
The FDA also wants the panel to address concerns (PDF) over potential risks to the reproductive health of women implanted with the device; whether clinical data in Medtronic’s pre-market approval application "provide reasonable assurance that the proposed device is safe for the specified indications and intended patient population based on how secondary surgeries were evaluated and whether any additional data or analyses that are needed;" and the higher incidence of serious back and/or leg pain with the Amplify device (10.5 percent among the implanted group and 8.5 percent among the control group).