FDA Panel Sends Mixed Signals on Silicone Breast Implants

Just one day after rejecting the revised premarket approval (PMA) application of Inamed Corp. (Santa Barbara, CA) for the company's silicone gel breast implants, FDA's general and plastic surgery devices advisory panel voted to recommend approval of similar implants from Mentor Corp. (Santa Barbara, CA).

In a 5–4 decision, the panel recommended that FDA issue a ‘not approvable' decision on Inamed's implants, then voted 7–2 to recommend Mentor's devices as ‘approvable with conditions.'

The last time that silicone gel implants were brought before FDA, in October 2003, the panel voted 6–3 to recommend approval of both companies' products. However, in January 2004, FDA rejected that advice and said that more product information and clinical data would be required before the devices could be considered for a return to the U.S. market.

In arriving at its decision to reject one implant yet approve another, FDA's panel cited differences in the data on rupture rates supplied by each manufacturer. In both cases, the data were drawn from 10-year performance estimates based on studies of the companies' products. Inamed reported rupture rates of 3.4% in augmentation procedures, 20.5% in breast reconstructions, and 10.9% in patients who were replacing older implants. Meanwhile, Mentor's reported data revealed much lower rupture rates: 0.5% in augmentations, 0.8% in reconstructions, and 4.8% for replacement implants.

Much of the long-term data submitted by the companies was based on extrapolated estimates. Inamed claimed that its main study was carried out for three to four years, in contrast to Mentor's two- to three-year time frame. Overall, Inamed reported that 2.5% of its devices ruptured in the first three years following implantation and estimated that 13.9% would rupture over a 10-year period. Neither manufacturer would assert how long silicone implants would last.

“Inamed did an excellent job of satisfying the majority of FDA's concerns,” said James Wells, MD, past president of the American Society of Plastic Surgeons (Arlington Heights, IL). “Unfortunately, the concern over long-term data regarding implant ruptures led the panel to issue a ‘not approvable' recommendation.”