This article has been updated with a statement from the Clinical Pharmacogenetics Implementation Consortium.
NEW YORK (GenomeWeb) – Inova Health System has decided to completely stop performing its suite of pharmacogenetic tests in response to a US Food and Drug Administration warning letter.
The FDA sent the warning letter earlier this month asking the Northern Virginia healthcare system's genomics laboratory to stop marketing its MediMap pharmacogenetic tests without its approval. In response, the lab said it will stop providing the tests entirely instead of pursuing FDA regulatory approval.
Medicare and most commercial insurers don't broadly reimburse for PGx testing, so it's unlikely that these tests were a major source of revenue for the health system. However, PGx testing was part of Inova's broader investment into personalized medicine expertise and technologies, and the healthcare system had been advertising its capabilities in this regard. In 2016, for example, Inova made PGx testing available to every baby born at its new women's hospital.
"After thoroughly reviewing the letter, which clarified the FDA’s approach to laboratory developed tests (LDT) for pharmacogenomics, Inova has decided to end MediMap tests," an Inova spokesperson said in a statement.
The FDA's warning letter to Inova is being closely scrutinized by other labs performing PGx testing. Some legal and pharmacogenetics experts said that the FDA's language in the warning letter raises legal questions about whether the agency has the authority to regulate lab-developed tests — a longstanding controversy between the FDA and the lab industry — and whether the agency is encroaching on the practice of medicine by asserting that "established" PGx indications are only those found in FDA-approved drug labeling (see in-depth story here.)
"The MediMap tests were intended to provide additional information to physicians in discussions with their patients regarding medication options," the spokesperson said. "Inova began offering this additional tool to prescribing physicians based on the National Institutes of Health-supported Clinical Pharmacogenetics Implementation Consortium (CPIC) and other industry guidelines with the understanding that our LDTs did not require the FDA's review and marketing authorization."
After a safety alert last November about unapproved PGx tests, the FDA contacted other labs and asked them to stop claiming in marketing materials and test reports that their tests can predict how patients will respond to specific drugs. Most firms obliged, according to a press statement from the FDA, but there are plenty of labs that, like Inova, are offering PGx testing for indications that are backed by guidelines from expert bodies such as CPIC, but not in FDA-approved labeling.
In a post on the PharmGKB website, co-principal investigators of the consortium, Mary Relling of St. Jude Children's Research Hospital and Teri Klein of Stanford University, responded to FDA's warning letter challenging the agency's assertion in the letter to Inova that "the relationship between CYP2C19 genotype and drug response to escitalopram and sertraline is not established." They pointed out that CPIC experts have concluded after a review of the literature that CYP2C19 phenotypes are actionable for these two drugs.
While they acknowledged that some labs may be marketing PGx tests for uses not supported by evidence, these two drugs aren't examples of this type of activity, according to Relling and Klein. To the FDA's concern that doctors may make inappropriate prescribing decisions based on PGx information not in agency-approved drug labeling, they pointed out that "the same criticism could apply to any test result, even for the liver function tests that are already included in the FDA-approved labels for these drugs."
"We agree that prescribers should be warned about the impact of hepatic function on drug effects; we advocate that pharmacokinetically based genetic tests may also be worthy of consideration by prescribers," they wrote. "Such a useful pharmacokinetically based genetic test includes use of CYP2C19 testing to assist with prescribing sertraline and escitalopram."
It remains to be seen how labs — some are part of other healthcare systems that have invested heavily in preemptive PGx testing while others are smaller startups — will react to Inova's decision to not engage with the FDA at all, but simply pull its tests from the market.
"Inova has contacted physicians to make them aware of this decision and to encourage them to discuss further care planning options with their patients," the spokesperson said. "Inova continues to devote our energy to becoming among the leading health systems in the nation with an unwavering commitment to clinical excellence."