* FDA: tests have not received marketing clearance
* 23andMe says it wants to address FDA's concerns
* FDA: action follows lengthy attempt to work with company (Updates with comment from NIH, American Society of Human Genetics)
By Toni Clarke and Sharon Begley
Nov 25 (Reuters) - The U.S. Food and Drug Administration has warned 23andMe, a company backed by Google Inc, to halt sales of its genetic tests because they have not received regulatory clearance.
23andMe, which was founded in 2006 by Anne Wojcicki, sells a $99 DNA test that the company says can detect a range of genetic variants and provide information about a person's health risks. Wojcicki recently separated from her husband, Sergey Brin, a co-founder of Google.
In a warning letter dated Nov. 22 and released on Monday, the FDA said products that are designed to diagnose, mitigate or prevent disease are medical devices that require regulatory clearance or approval, "as FDA has explained to you on numerous occasions."
The privately held company, which is based in Mountain View, California, acknowledged receipt of the letter and said in a statement that "we recognize that we have not met the FDA's expectations regarding timeline and communication regarding our submission."
The FDA said some of the intended uses of the company's Saliva Collection Kit and Personal Genome Service (PGS) are particularly concerning, including risk assessments for certain cancers.
The agency said false positive tests for certain breast or ovarian cancers could lead a patient to undergo preventative surgery including mastectomy, intensive screening or other potentially risky procedures. A false negative could result in a failure to recognize and act on an actual risk.
23andMe will not be able to sell its tests for medical purposes until it submits the necessary data.
The FDA has not cleared any genetic tests that are offered directly to consumers.
Kathy Hudson, deputy director for science, outreach, and policy at the National Institutes of Health, said the FDA action clarifies its expectations for direct-to-consumer genetic testing. "NIH believes genetic information has a great potential to improve human health, but there need to be reliable, validated tests," she said.
One concern is that the results of genetics research, especially that linking a DNA variant to the risk of a particular disease, might apply to some ethnic groups but not to others. As a result, a consumer might think she has an elevated risk of some illness when in fact she does not.
On its website "the company quotes numbers for risk from published scientific papers, but you'd have to be pretty sophisticated to know that if the study was done on western Europeans it might not be relevant to you if you're Chinese," said geneticist Dr Jeff Murray of the University of Iowa and president of the American Society of Human Genetics (ASHG).
The FDA said in its letter that 23andMe had submitted applications in July and September of 2012 for several uses of its saliva test but had failed to address issues raised by the agency or to provide additional information requested. As a result, the FDA said, the applications "are considered withdrawn."
The company said its relationship with the FDA is "extremely important to us and we are committed to fully engaging with them to address their concerns."
Dr. David Agus, a professor of medicine and engineering at the University of Southern California and founder of Navigenics, one of the first personal-DNA testing companies, said the FDA's letter to "is not a death knell to personal DNA testing" but should be a wake-up call. "We have to be transparent with consumers about what sequencing their genome can and cannot reveal," he added.
Navigenics was acquired last year by Life Technologies Corp.
The FDA said it had been "diligently working" to help 23andMe comply with the law, and spent significant time evaluating the intended uses of the DNA-testing product. It said it provided detailed feedback to the company through more than 14 face-to-face and teleconference meetings, hundreds of email exchanges, and dozens of written communications.
"However, even after these many interactions with 23andMe, we still do not have any assurance that the firm has analytically or clinically validated the PGS for its intended uses," the FDA said.
While 23andMe may not have been communicating with the FDA, Wojcicki has been talking at length to the media. Earlier this month she told the New York Times that her company had mapped the genotypes of 475,000 people over the last five years and expected to "hit a million" in the first quarter of 2014.
In a recent article in Fast Company, Wojcicki said her ultimate goal was to sign up 25 million people. "Once you get 25 million people, there's just a huge power of what types of discoveries you can make," she said.
The company name refers to the 23 pairs of chromosomes that make up each individual's genome.
After years of trying to obtain from 23andMe the information it needs to ensure the tests are accurate, the FDA appears to have finally lost patience.
"I think this will certainly grab the attention of a lot of other companies out there," said Joseph McInerney, executive vice president of the ASHG.
(Reporting by Toni Clarke in Boston and Sharon Begley in New York; Editing by Matthew Lewis and Tim Dobbyn)