FDA Review Sought Of Data on Implants
Friday, October 13, 2006
A consumer activist organization yesterday asked the Food and Drug Administration to investigate what it considers a possibly criminal attempt to suppress information about the risks of the new generation of silicone breast implants.
In a letter to the FDA's administrator, Public Citizen said it learned of test results -- some new, some reinterpreted -- from a scientist at implant maker Mentor Corp. who says he could not persuade his bosses to forward the data to the regulatory agency.
The scientist had worked for 15 years for Mentor, which is based in Santa Barbara, Calif. He was let go earlier this year in a company reorganization, although he thinks his protests to superiors were part of the reason.
The FDA is in the late stage of reviewing applications by two companies to sell once more silicone breast implants for general use. Last year, the agency gave preliminary approval for the devices on condition that Mentor and a competitor, Inamed (now part of another company, Allergan), complete required tests.
Currently, most breast implants used in the United States are filled with saline solution -- salt water. Silicone implants can be used only under limited conditions, generally in FDA-approved studies at specified hospitals.
Many implants are used by women who have had a mastectomy for breast cancer, but most of the 250,000 sold each year are for breast enhancement. That number is expected to rise if the more popular silicone implants are allowed back on the market.
"This new information is compelling enough to warrant a reassessment of the FDA's position," Sidney M. Wolfe, the physician who heads Public Citizen, said in a letter to Andrew C. von Eschenbach, the FDA's acting commissioner. Wolfe added that unless the agency recommends a criminal investigation of Mentor, "it will encourage [Mentor] and other device manufacturers to selectively send the agency only those studies that put their products in the most favorable light."
The former Mentor scientist said he is not certain his findings mean that silicone implants are less safe than believed. But he said he thinks the information is relevant to the discussion and further studies need to be done.
"The data exists. It can't be refuted," he said yesterday. "I didn't want to get Mentor in trouble. I didn't want to point a finger at the FDA. The intention was to get the damn data reviewed and put in the total picture."
The scientist requested anonymity because he is looking for a job and does not want to be identified as a whistle-blower.
Two of the four issues he raised to his employers, and later to the FDA after he left Mentor, concern "low molecular weight siloxanes" -- the smaller members of a large family of silicone compounds in the implants' gel. Over time, some can pass through the plastic skin of the implant into the body.
In one of Mentor's studies, implants were submerged in the blood serum of pigs for a prolonged period. Chemists measured the amount of small silicone molecules in the liquid and found essentially no increase.
The scientist said he later determined that the silicone molecules were sticking to proteins and fat in the pig serum, making them uncountable. He devised a way to use a solvent to release them.
"The diffusion data that was submitted to the FDA is meaningless," he said in an interview.
But, he added, "even when we were aware in the corporation that this data had no meaning, we didn't inform the agency. As a matter of fact, the person who had oversight of my department tried to give validity to the data basically with a hand-waving approach." He said he considered that "intentional deception."
In another study, company scientists measured the concentration of various silicone compounds in implants that had been removed from women, some after a decade of use. Curiously, they found higher concentrations of small compounds than in implants that had never been used. For some molecules, there had been a tenfold increase, from 10 parts per million to 100 parts per million.
Why this occurred is unknown. Two possibilities are that body heat or motion may have caused large silicone molecules to break down into smaller ones.
"The bottom line is that somebody needed to go and look at this," the scientist said.
In a statement yesterday, FDA spokeswoman Heidi Valetkevitch said the agency "took the whistle blower allegations very seriously."
She said the agency "found no evidence of wrongdoing and nothing that would raise questions about the safety of the product under review or the integrity of the data submitted to FDA."
She added that manufacturers must submit any new data that could affect the safety and effectiveness of their products, but that "our investigation and inspection determined that the company's test results did not fall into this category."
In a statement, Mentor said: "During July, representatives from FDA visited our Santa Barbara facility. They asked questions and reviewed documents specific to our preclinical testing. To our knowledge, all questions were answered to the satisfaction of FDA."