SILICONE-CONTAINING IMPLANTS CONTINUED MARKETING
This article was originally published in The Gray Sheet
Executive Summary
SILICONE-CONTAINING IMPLANTS CONTINUED MARKETING will be allowed by FDA while the agency reviews data demonstrating that substitute silicone materials used in the implants are "not substantially different" from those supplied by Dow Corning, FDA says March 5. The agency's decision is in reaction to Dow Corning's announcement that it will withdraw its "implant grade" silicone elastomers from the market on March 31 ("The Gray Sheet" Dec. 7, I&W-10). The March 5 "strategy for management of devices" affected by the removal of Dow Corning's products states that FDA will allow manufacturers of agency-approved silicone containing devices "to continue to be marketed" while special regulatory applications containing test data on substitute materials are evaluated. The Dow Corning action will remove from supply channels five silicone-based materials (see box for list of materials being withdrawn). In addition, the firm is denying access to its device master file for these materials effective immediately. At least two firms, Nusil and American Silicone, have indicated their interest in supplying silicone materials to implant manufacturers. In its March 5 document, FDA says that its "staff has evaluated the impact of this decision by Dow Corning and is concerned about the continued availability of devices manufactured from silicone elastomer." FDA's silicone strategy is designed to ensure that there is not a shortage of devices while manufacturers switch to new suppliers. According to the strategy, FDA is working with industry to develop a list of tests "which will allow us to define that a silicone elastomer manufactured by a firm other than Dow Corning is not different from the Dow Corning elastomer." The document requires holders of approved 510(k)s and premarket approval applications to evaluate their substitute materials using tests on the list. The firms must then make submissions to the agency referencing the test data to demonstrate that the new materials are "not substantially different" from the ones described in their original applications. FDA says that it "will establish a separate review cycle to expedite the review" of these applications. The strategy requires that firms making the special submissions to the agency retain copies of their materials testing data for inspection by FDA "as part of routine GMP inspections." Based on the special submissions, FDA will determine if certain types of devices also will require 510(k)s and PMA supplements for their new materials. Firms that make these products will submit applications based on completion of "certain physical and chemical characterizations and certain of the biocompatibility testing such as described in the Tripartite Agreement or [International Standards Organization] Biocompatibility Standard on the finished products." FDA will "negotiate" with the firms to determine completion dates for the tests. "If the testing is not completed on time or if the testing demonstrates that the devices are not safe, the firms will withdraw the products," FDA says. The agency also notes that it "is likely to require" discretionary postmarket surveillance studies "for products where the long-term implant safety of the device is not well established with clinical data." FDA says that depending on the success of the strategy it may develop a similar method for managing DuPont's phase-out of its raw materials used in permanently implantable devices. DuPont's withdrawal began Jan. 15 ("The Gray Sheet" Feb. 8, p. 12).