FDA panel wants info on metal implant reactions (TMGPulse)

An FDA panel will meet this week to discuss immunological responses to medical device implants made of metal, including artificial hips and the Essure permanent birth control device.

The Immunology Devices Panel of the agency’s Center for Devices and Radiological Health is seeking scientific information on how metal implants or inserts elicit a prolonged and/or heightened immunological inflammatory response.

Corrosion of the metals used in artificial hips, for example, have been linked to metallosis, or metal poisoning. Symptoms include bone and tissue death, implant failure and severe pain. Implant makers have reached billions of dollars in legal settlements and researchers continue to study and test alternatives.

Bayer’s (ETR:BAYN) Essure inserts are metal coils made of polyester fibers, nickel, titanium, platinum, silver-tin and stainless steel. Designed for implant in the fallopian tubes, Essure was pulled from the U.S. market in 2018 after women reported suffering a variety of ailments after implant, including pain, bleeding and autoimmune disorders.

The discussion on Wednesday and Thursday will include patients’ local and systemic signs or symptoms or immunological response to metal-containing devices as well as the gaps in the scientific understanding of the interactions between the immune system with metal implants/inserts or their corrosion products.

The panel also wants information on factors that may increase or decrease a patient’s susceptibility to a heightened or prolonged response to a metal implant/insert, and the research needed to understand and mitigate the impacts of these factors. They include:

  • Sex, age and/or female reproductive status.
  • Medical comorbidities such as allergy, connective tissue diseases, other inflammatory and autoimmune diseases.
  • Modifiable behaviors such as tattooing, smoking and wearing metal jewelry.
  • Genetic markers and/or other biological or demographic variations.
  • Location of device implant.
  • Duration of implantation.
  • Specific metal or metal alloy compositions.
  • Surface and coating characteristics.
  • Manufacturing processes.
  • Corrosion/degradation products or other release of substances.

The panel also wants information on the status and clinical usefulness of diagnostic/prognostic tests administered before and after implantation to assess or manage patient reactions to implants. Experts will be asked to specify unknowns about these tests, the next steps to develop methods to reliably predict an individual’s risk of heightened response and to monitor reactions after implantation.

Finally, the panel will ask for testimony on the need for nonclinical biocompatibility assessments
of metal implants/inserts and their potential to evoke and modulate immune and inflammatory responses. Immunological responses to dental amalgams will also be discussed.

An FDA research document on the topic may be found here.

Separately, a pair of scientists at Argonne National Laboratory said last summer that they are seeking to patent a method that they say does a better job than standard ASTM tests of showing how well hip implants will endure conditions in the human body before corrosion sets in.