Citizen Petition Urges FDA To Control Diagnostic Tests

A citizen petition was filed with the US Food and Drug Administration (FDA; Rockville, MD, USA) urging the agency to take on greater control of diagnostic tests that are intended to guide therapeutic decisions and to regulate all laboratory-developed tests (LDT).

The biopharmaceutic firm Genetech (South San Francisco, CA, USA) which filed the citizen petition, is involved in an issue that disturbs many molecular diagnostic manufacturers who are awaiting the FDA's final guidance on in vitro diagnostic multivariate index assays (IVDMIAs). A draft guidance on IVDMIAs was issued in September 2006. The FDA said then that such tests, normally overseen by Clinical Laboratory Improvement Amendments (CLIA) regulations, must instead be cleared by the agency because of their complexity. CLIA regulates all laboratory testing (except research) performed on humans in the United States for The Centers for Medicare & Medicaid Services (CMS).

According to a draft document, which consisting of nonbinding recommendations by the FDA (July 26, 2007), IVDMIAs raise significant issues of safety and effectiveness. These types of tests are developed based on observed correlations between multivariate data and clinical outcome, such that the clinical validity of the claims is not transparent to patients, laboratory personnel, and clinicians who order the tests. They do not fall within the scope of LDTs over which FDA has generally exercised enforcement discretion.

In general, an IVDMIA might use measured or observed values of multiple variables, such as a patient's age, weight, metabolite level, and gene expression levels. A unique interpretation function specific to the IVDMIA would then combine and analyze these variables to yield a score. The intended use of the IVDMIA, for example, would be to diagnose disease or predict risk of disease based upon this score.

Examples of these "devices" are: gene expression profiling assay for breast cancer prognosis; and a device that integrates quantitative results from multiple immunoassays to obtain a qualitative "score” that predicts a person's risk of developing a disease or condition.

Early in 2008, several industry representatives and pharmacogenomics advocates strongly criticized the IVDMIA guidance, calling it untenable, and potentially illegal. Presenters at that FDA meeting claimed that the document failed to clearly define what the FDA considers IVDMIAs; does not explain how the agency's regulations would merge with CLIA's guidelines; and would lower incentive to innovation in personalized medicine.

While Genentech argues for greater FDA oversight of LDTs, the Washington Legal Foundation (Washington DC, USA) filed a citizen petition in 2006 requesting that FDA does not regulate LDTs as medical devices. The FDA has not yet responded to that petition.

Related Links:
US Food and Drug Administration
Genetech
The Centers for Medicare & Medicaid Services
Washington Legal Foundation