- Two widely used categories of medical devices — metal-containing implants and dental amalgam — are set to go under the microscope Nov. 13-14, per a notice Monday announcing a public meeting of the Immunology Devices Panel of the Medical Devices Advisory Committee. Ahead of the event, the agency also put out two scientific reviews, first teased in March: one on biological responses to metal implants, another on adverse health effects related to mercury from dental amalgam.
- "Recent postmarket issues with some metal-on-metal orthopedic implants and gynecological metal-containing implants have raised questions about the potential for some patients to develop unexpected or heightened biological responses to the implant," FDA wrote in its announcement.
- The agency is seeking expert advice on which patient characteristics or metal properties may put an individual at higher risk for developing an adverse reaction, and what research could be conducted to better understand the issue and minimize risk.
FDA has devoted several advisory committee meetings this year to discussions of specific device types' malfunctions or related patient complications, including devices including transvaginal mesh, breast implants, surgical staplers and paclitaxel-coated devices.
But the question for the Immunology Devices Panel spans specialties from cardiology and orthopaedics to gastroenterology and neurology. Regulators are seeking a better understanding of how different types of devices and their materials have the potential to prompt an adverse immunological response and what might make certain patients more susceptible than others.
Included in the two-day discussion is dental amalgam, which FDA said is relevant because of its potential to expose patients to mercury compounds "and some purported similarities in the adverse biological responses and clinical manifestations elicited by some dental amalgams to that of traditional metal implants."
Now off-the-market, metal-on-metal hip replacement systems are among the devices prompting further scrutiny of device materials. In numerous implanted patients, the devices gradually degraded, releasing metal wear particles and ions into the bloodstream, FDA has said. Some of these patients, in addition to having damage in surrounding bones, soft tissues and muscles, also had damage to the heart, kidneys and thyroid.
Other discussion topics for the panel laid out in a related statement Monday from Center for Devices and Radiological Health Director Jeff Shuren include whether current biocompatibility standards are adequate and if there is additional scientific information FDA should consider in pre- or postmarket review of these devices.
"The FDA continues to believe that the benefits of metal or metal alloys in medical device implants outweigh the risks for most patients," Shuren said in a statement Monday, but added the FDA continues to "explore ways" to modernize its review of medical device materials.
The meeting will take place in Gaithersburg, Maryland from 8 a.m. to 6 p.m. Nov. 13-14. FDA is creating a public comments docket for the meeting. It will accept comments until Dec. 16. If received by Oct. 28, the comments will be provided to the committee.