FDA ramps up scrutiny of materials in medical devices
The FDA said today it has begun more closely scrutinizing the roles of certain materials associated with harm to patients who have breast implants, nitinol-containing devices, metal-on-metal hip implants and devices made from animal-derived substances.
It’s the latest in a series of statements the agency has issued following increasingly harsh public criticism of its efforts to regulate the medical device industry. In the past year, Netflix’s documentary “The Bleeding Edge” and the International Consortium of Investigative Journalists’ “The Implant Files” series ripped the agency and the industry over patient injuries attributed to faulty devices. The FDA has been particularly faulted for its 510(k) clearance pathway, under which it allows devices that are similar to previously approved technology to undergo a less strenuous review before they can be sold.
While the industry shrugged off “The Implant Files,” the FDA released plans for updating the 510(k) process. The agency and the industry emphasized that the critical reports did not adequately acknowledge the benefits of medical devices to millions of people. Also this week, the FDA announced plans to reorganize its Center for Devices and Radiological Health (CDRH), combining previously separate premarket review, postmarket surveillance and compliance offices and into one “super office” to better monitor products through their total product life cycle.
A closer look at nitinol
Today, the agency said it plans to publish new draft guidance on medtech’s use of nitinol, with recommendations on technical testing and labeling, and requests for specific manufacturing information and other factors that could affect the flexible material’s breakdown in the body. In November, the FDA released steps it is taking to maintain its oversight of Bayer‘s (ETR:BAYN) Essure permanent birth control device following its removal from the U.S. market last summer, including extensions and revisions to a required post-market study of the device.
More medtech manufacturers have begun incorporating nitinol in cardiovascular stents, guidewires and other devices used in minimally invasive procedures because the metal is flexible and bendable and can spring back to its original shape, the FDA said. The agency’s announcement hinted that an implant’s location may contribute to its potential to cause an immune or inflammatory reaction. Essure patients have associated that device with chronic fatigue, cognitive issues and muscle pain in addition to excessive bleeding. Bayer has denied claims that Essure is less than safe and effective.
The FDA also said it is taking a closer look at silicone breast implants, whose recipients have reported capsular contracture, implant rupture and breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). More confirmed cases of BIA-ALCL have been reported in patients with textured surface implants than in patients with smooth-surface breast implants, the FDA noted. Other patients believe their implants may have triggered immune system responses such as chronic fatigue, cognitive issues and muscle pain.
The agency has scheduled a public meeting of its general and plastic surgery devices panel for March 25-26 to discuss issues that patients have associated with breast implants. It has been working with two different breast implant registries to learn more about how these devices perform and interact with the body’s tissues at the cellular and organ levels. The FDA also said it is working with multiple stakeholders to advance the development of the National Breast Implant Registry (NBIR) to provide a platform for evaluating real-world data on the safety and performance of breast implants.
Metal-on-metal hip implants
Metal-on-metal hips are no longer sold in the U.S., but many patients still have the devices implanted and postmarket studies continue. The FDA reported that studies on more than 2,000 explanted devices revealed heavier wear between the metal ball and metal socket than what was expected based on tests performed on the devices before the agency allowed them on the market. Manufacturers have agreed to shell out more than $1 billion to settle lawsuits over the devices.
Interim results from postmarket studies also show significantly higher blood levels of metal ions (cobalt and chromium) in patients with metal-on-metal hip implants compared to those without metal implants. However, some patients with higher blood levels had no complications while others with low blood levels reported severe symptoms. The agency said other factors such as device design or surgical placement may have contributed to greater wear-down of the devices and elevated metal ion levels.
The FDA said it is working with standards development organizations, such as the American Society for Testing and Materials, to develop new standards to improve how metal-on-metal hips are evaluated and identify additional testing protocols for new metal-on-metal devices that are submitted to the FDA for review.
The agency will also hold an advisory committee meeting this fall to discuss metal implants and the potential risk for certain patients to have exaggerated immune and inflammatory reactions to these metals. Prior to the meeting, it will release a peer-reviewed white paper that summarizes the current scientific knowledge regarding metal implants, including how the devices’ structure and function are affected by the body’s tissues, muscles and blood supply and how the metal components dissolve and interact with immune cells.
“These efforts are just a few aspects of our ongoing evaluation of the effects of materials in at-risk patients. Our goal in taking these steps is to ensure that the benefits of devices made of metal materials continue to outweigh their risks,” said FDA Commissioner Dr. Scott Gottlieb and CDRH director Dr. Jeff Shuren in a prepared statement. “For the vast majority of patients, this is the case and will remain the case as we go through these steps. However, for certain small subsets of patients who exhibit sensitivities to select materials, we must determine what additional actions we should take to make sure they are protected and understand the unique risks they may encounter.”
Animal materials in devices
The agency also said it is working to improve the safety of devices made from animal-derived materials such as additives used on device coatings or heart valves made from pig tissue. These materials may carry a risk of transmitting infectious disease when improperly collected, stored, or manufactured, contributing to neurodegenerative disorders such as Bovine Spongiform Encephalopathy (BSE) or Mad Cow Disease. Yesterday, the FDA issued final guidance on Medical Devices Containing Materials Derived from Animal Sources, recommending how to minimize the risk of transmitting rare but serious infectious diseases while still providing patients access to beneficial devices made from animal-derived materials.
“More closely evaluating the potential for certain materials to cause immune/inflammatory reactions in a small number of patients may improve our understanding of materials, help uncover ways to identify patients predisposed to these reactions and improve the overall safety and performance of medical devices,” Gottlieb and Shuren concluded. “This is part of our continuing effort to advance opportunities for enabling modern materials to improve the performance of medical devices while also advancing our assurance of safety for these products. We look forward to providing updates about our progress and ongoing research. We believe our continuing efforts will ultimately provide patients and doctors with better access to more effective and safer medical devices.”