Close vote at Amplify panel meeting

GAITHERSBURG, MD -- An expert FDA panel has cast a narrow vote on Medtronic's (NYSE: MDT) Amplify matrix device, which uses a bone morphogenic protein to stimulate bone growth in patients with degenerative disc disease (DDD). Although six members said the benefits of the device outweigh the risks, five said no while three abstained. Many panelists wanted more data, with some saying that they didn't know whether it made a difference in patients.

The panel first took a vote on the safety of the device. Nine said there is "a reasonable assurance" that the device is safe for the indication for posterolateral fusion treatment of single level lumbar DDD. Four indicated they didn't think it was safe and one panelist abstained. Amplify had been linked to higher cancer malignancy than alternative procedures. The company says the difference isn't statistically significant, but the FDA wanted the panel to assess this risk. During the lively meeting, panelists kept coming back to the cancer question. In fact, ensuring patient safety came up numerous times, with one panel member asking, "Is this something you want to put in Aunt Millie?" 

The FDA's Nona Colburn expressed the agency's concerns about the device during her presentation, highlighting some of the statistics in the agency's briefing documents.  To date, there have been 20 adverse events related to cancer (15 events in 12 patients in the Amplify group versus five events in five patients in the control). In addition, she pointed out that one study subject had died from a methadone overdose. One of the exclusion criteria was alcohol and/or drug abuser currently undergoing treatment for his or he addiction. That the methadone user and people who were diagnosed with cancer fairly early in the study--despite the exclusion criteria--somehow made it into the study was problematic.

Colburn also noted that the Amplify group had a higher incidence of serious adverse events related to back and/or leg pain compared with the control group (10.5 percent versus 8.5 percent, respectively). Questions were also raised about reproductive toxicity.

A separate vote was taken on whether the product is effective; 10 said yes, three said no, and one member abstained. Again, panel members said more data was needed.

Leerink Swann analyst Rick Wise estimates that, in the first year after gaining approval, Amplify could add $130 million to $175 million in sales to the spinal franchise, the Wall Street Journal notes.

- see the WSJ's report