The U.S Food and Drug Administration sent warning letters to gene testing companies over marketing and selling unapproved direct-to-consumer (DTC) tests aimed at predicting drug response.

The FDA letters posted Monday were addressed to privately held companies DNA4Life, DNA-CardioCheck, Inc. and Interleukin Genetics, Inc., and targeted diagnostic tests that the regulatory agency said were being marketed to the public without prior clearance.

James Woods, FDA deputy director for patient safety and product quality under in vitro diagnostics, said in each of the letters that the agency was unable to find a clearance number for the tests in question, instructing the firms to show proof of clearance or offer a rationale behind why they need not be cleared.

The warning letter for DNA4Life cites the firm's Pharmacogenetic Report, done to predict how people will react to more than 120 of the top prescribed drugs, as uncapproved. The letter addressed to DNA-CardioCheck, Inc. zeroes in on the firm's tool for testing genetic markers associated with deep vein thrombosis, thrombophia, stroke, and cardiovascular disease. As for Interleukin Genetics, Inc. the FDA points out that its PerioPredict Genetic Test, Osteoarthritis Genetic Test and Weight Management Genetic Test have not been cleared.

FDA press officer Eric Pahon said that while the agency knows that many consumers want information on their genomes and genetic risks for disease, not all DTC tests are being appropriately offered.

“[O]thers may need to demonstrate that they are safe and effective and that appropriate controls are in place to mitigate risks,” Pahon said.

The FDA letter for Interleukin Genetics referenced a 2010 correspondence where it called out the firm for the same move. Interleukin Genetics responded that theirs had been laboratory developed tests (LDTs), which currently do not need to be FDA-cleared.

The FDA, however, asserted that the test followed the DTC model and that it will continue to monitor any tests being marketed to consumers directly. In 2014, it disclosed plans to fortify its LDT oversight through enforcing pre- and post-market review for higher-risk LDTs.

In an earlier interview, Louisiana-based DNA4Life said its test, launched last month, did not require FDA clearance.

Back in September, a similar letter was sent to Pathway Genomics for its cancer detection test, where Woods said the FDA could not find published evidence that the test or any similar one had been clinically validated.

FDA also has a two-year issue with company 23andMe for its DTC personal DNA testing service, which the agency ordered to be taken off the market in 2013. Last month, the company relaunched a limited number of genetic test products for carrier screening, amid still not having FDA approval for marketing or selling its drug response predictor tests.

According to Dr. Josh Peterson, pharmacogenetics expert at Vanderbilt University, doctors –just like patients – are struggling to understand or interpret the results of DTC tests. And this may be part of the core of FDA’s concerns.

“I’m an internist. That would be one of my concerns as well,” warned Peterson.

Photo: USFWS Mountain-Prairie | Flickr

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