|Superion Interspinous Spacer--Courtesy of VertiFlex|
An orthopedic advisory panel voted to approve Vertiflex's PMA application to the FDA for its Superion Interspinous Spacer (ISS), a spinal implant designed to treat moderate lumbar stenosis and pain, numbness and/or leg cramps related to the condition.
The orthopedic panel of 8 outside experts took the device under review following concerns by the regulatory agency about fractures to the back of the spine resulting from its use. The panel voted 5 to one (two members abstained) that they felt there was reasonable assurance the ISS was safe to use, and that it met the criteria specified in the proposed indications. On the third vote, which asked the panel if the probable benefits of device outweighed the possible risks, there were four "yes" votes, two "no" votes and two abstentions.
"The panel was asked to judge whether the spinous process fracture by itself was a substantial safety issue and I think the panel generally felt the spinous process fractures were not a substantial safety issue, but (it) did raise concerns about the possible loss of effectiveness with the device in time," Raj Rao, MD, chair of the panel, told Healio.com.
Although the FDA isn't required to follow lock-step with a panel's decision, the regulatory agency typically adheres to those recommendations. If approved by the FDA, the ISS would compete with Medtronic's ($MDT) similar X-Stop Spacer interspinous implant.
The ISS met its primary clinical endpoint of a noninferior success rate compared to the X-Stop Spacer. At 24 months the ISS had a success rate of 52.7% compared to the X-Stop's 50.2%. Although both devices offer an alternative to invasive spinal fusion surgery, the procedure has fallen out of favor among insurers, who suspect it is overperformed.
While the ISS met its overarching goal, the FDA noted the more granular data showing that 8.5% of X-Stop patients in the clinical trial (or 17 out of 201) had a spinous process fracture, compared to 16.3% (or 31 out of 190) of ISS patients. A spinous process protrudes from the back of each vertebra and is an attachment point for muscles and ligaments that move and stabilize the vertebrae. The ISS is implanted in between adjacent spinous processes of neighboring lumbar vertebrae, located in the lower, weight-bearing portion of the spinal column.
VertiFlex currently sells the 510(k)-cleared Totalis Direct Decompression System to perform minimally invasive direct decompressions of the lumbar spine.