A prominent consumer advocacy group is once again calling for the US Food and Drug Administration (FDA) to make changes to the way it regulates medical devices, saying that the high-profile failure of one implantable medical device is evidence that all others should be classified as high-risk products and held to more stringent testing standards.
Metal-on-metal hip implants were cleared in recent years through FDA's 510(k) pathway, which allows for companies to skip clinical testing under the theory that because the devices are substantially similar to an already-approved "predicate" device, they are safe for use.
In the case of Johnson & Johnson subsidiary DePuy's metal-on-metal hip implant, however, that theory was put to the test, eventually with disastrous results. The device was cleared in 2008 despite having made three changes: The joint articulation of the device was changed to all-metal, the surface of the femoral head was changed to metal, and the size of the femoral head size was increased. Those changes were still in the acceptable range for the device, which is known as a "split predicate" device.
However, the device would be recalled just a few years later after DePuy started receiving numerous reports about problems with the device, including that the metal-on-metal design was causing bits of metal chromium to shear off the device, causing pain to patients and requiring surgical revisions.
An Appropriate Use of the 510(k) Pathway?
At issue for many safety advocates was a simple question: Should any implantable medical device be allowed to skip clinical testing before being allowed to reach US consumers?
For one prominent group, Consumers Union, the answer was a resounding "no."
Leveraging its considerable membership base, the group began an advocacy campaign aimed at convincing FDA and Congress to make changes to the 510(k) process, saying that it was unacceptable that so few medical devices ever made it through the considerably more rigorous premarket approval (PMA) process.
At the time, Consumers Union said it wanted permanently implantable medical devices and life-sustaining devices to go through the PMA process. In addition, it said it wanted to make sure all medical devices approved by FDA prior to 1976, when it first started to regulate medical devices, could not be used as a predicate device for the purposes of a 510(k) premarket notification application.
Those efforts, however, went nowhere. Despite its attempts to get legislators to listen during the markup of the then-draft version of the Food and Drug Administration Safety and Innovation Act (FDASIA), the recommendations did not end up in the final version of the bill.
But if the 510(k) process at large has remained the same, FDA has nevertheless moved to make some changes on its own-changes applauded by Consumers Union.
In January 2013, FDA announced it would require all hip joint metal-on-metal semi-constrained prosthesis devices to have an approved PMA before being allowed to be marketed.
The new PMA requirements for metal-on-metal hips are scheduled to begin 90 days after the rule is finalized. Devices already on the market will be allowed to continue being marketed while FDA reviews their PMA or Product Development Protocol (PDP) submission, FDA said, so long as it is "timely filed" within 90 days of the date of issuance. After that time, the devices would be deemed "adulterated."
That decision got support from Consumers Union, which said that though the decision was "too late for thousands of people who have been harmed by these implants," it nevertheless strongly supported the proposal's requirements.
But Consumers Union is also taking the chance to re-ignite its campaign for more stringent requirements for other devices. Its 18 April 2013 letter to the US Food and Drug Administration (FDA) is co-signed by "more than 11,000 people," it said, all of whom express their support with the idea that high-risk implants need to undergo the PMA process before being allowed to go to market.
"In addition, we strongly encourage the FDA to review and re-classify to PMA status all Class III implantable medical devices," the group added, noting that other devices, such as surgical mesh implants, represent similar threats to consumer safety.
"Please move quickly to bring metal on metal hips and all other high risk implants under the PMA process so clinical evidence will be required to show their effectiveness and safety," the group's letter concludes.