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FDA panel not yet prepared to set lumbar spine device guidelines
Manufacturer and professional society representatives suggest basing controls on indications and goals, not randomized clinical trials.
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The FDA needs more data on certain devices used to treat mild to moderate low back pain before setting strict clinical study guidelines for them.
That was the conclusion reached by the agency’s Orthopaedic and Rehabilitation Devices Panel at a recent meeting. The panel did not vote. Rather the meeting was informational, with the panel’s responses to FDA questions serving as recommendations.
The discussion focused on interspinous process placers, nucleus replacements and pedicle screws/ dynamic fixators. The panel heard several presentations and addressed FDA questions about target populations, study endpoints, control populations and study designs.
Representatives were on hand speaking for device manufacturers and professional societies, including the Orthopaedic Surgical Manufacturers’ Association, North American Spine Society, Spine Arthroplasty Society, American Association of Neurological Surgeons, Spine Wave Inc., Zimmer Spine, Stryker Spine, Abbott Spine, and Emerging Technologies Research and Development.
Sixty to 80% of adults suffer low back pain at some point in their life, which causes absenteeism and accounts for a large percentage of U.S. health care spending, said Jonathan Peck, of the FDA’s Orthopedic Devices Branch. Common low back pain treatments include spinal fusion or decompression, motion preserving devices and, more recently, total disc replacement, Peck said.
Patients with mild or moderate disease may not be ideal surgical candidates, Peck said. Nonsurgical options include medication, physical therapy, patient education and injections. Potential surgical options include fusion, TDR, discectomy and laminectomy, he said.
Peck expressed concern about randomizing patients to undergo invasive procedures they may not need.
An entirely new approach
Care standards, indications and outcomes should dictate decisions about when to intervene surgically, said Sally Maher, an Orthopaedic Surgical Manufacturers’ Association attorney.
“One must consider the standard of care, the intended use of the device, the patient population for which the sponsor seeks approval for the device to treat, the risk of the investigational device and the health benefits the sponsor seeks to prove,” Maher said.
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Another spokesman suggested that entirely new approaches to government approval. “I believe that device effectiveness should be based more on alleviating pain and restoring function rather than on radiographic measures,” said Hallet H. Mathews, MD, of Richmond, Va. “Spinal stability without pain relief is not an effective device treatment. Conversely, both patient and surgeon may be satisfied even if the radiographic criteria are not met but the patient is pain free and has resumed a desired lifestyle.”
Mathews recommended using Oswestry, Visual Analog and SF-36 scales alone or together to evaluate patients’ outcomes. “Perhaps there are more newly validated and perhaps more sensitive measures to detect early postop treatment benefits,” he said.
“In the past, we tried to force-fit studies into a certain design to decrease the amount of time needed to gain regulatory approval,” Mathews said. “We should not automatically jump to the requirement for a randomized control clinical trial,” Mathews said. “It is legitimate to design studies with patients as their own controls or with historical controls.”
He called instead for basing controls on indications and treatment goals, not the devices themselves, and added that short-term data may be enough to determine a device’s safety and efficacy when the goal is spinal stability, not fusion. A year’s data, or less, may suffice. He also called for changing efficacy standards.
Stephen Hochschuler, MD, a founding SAS board member and first vice president of the society, urged the FDA to change its device approval process.
“I believe it’s time to rethink the entire analytical process, to expedite the development of new technologies while protecting our patients,” Hochschuler said.
Case-by-case review
“It’s not appropriate at this time to provide strict answers to any of these questions,” said Michael J. Yaszemski, MD, PhD, who led the FDA’s questioning. “I think we’re too early in the evaluations of these types of devices to make any global statements that will bind either physicians, patients or device manufacturers into a narrow pathway.”
Yaszemski suggested focusing on a study’s scientific validity and a device’s risks and benefits, and studying each device on a case-by-case basis.
“There is such a wide variety of implants and diseases and various combinations that it’s probably too early to make any specific recommendations or requirements,” added panel member Choll W. Kim, MD, referring to spacers and pedicle screw systems. “But I would say that a standard six-month pre-treatment trial of conservative therapy is probably not a number that we should be relying on. It makes sense for certain disease types, but for some of these other disease entities and implants, that may be too long or it may be too short.”
However, “general” guidelines would decrease sponsors’ and the investigators’ uncertainty in evaluating premarket applications for devices, Kim said.
Waiting six months for surgery on a herniated disc “doesn’t seem reasonable,” Kim said. However, a six-month wait for a nucleus replacement or lumbar stenosis device is acceptable, he said.
“We need to really work together with the study sponsors to come to some agreements, almost on a case-by-case basis,” Kim said.
“In general, the panel believes that if the device is less invasive, smaller changes in pain levels may be acceptable, higher delta levels may be acceptable and, again, everything should be judged based on a specific device and the mechanism of action,” said Acting Chair Sanjiv H. Naidu, MD, PhD. “And, again, not all of the devices that we’re talking about today are off the same mechanism. I mean, some are definitely less invasive than others.”
The FDA conducted the meeting in September.