I have posted a number of previous notes about IVDMIAs. Please refer to them if you need some background reading about this category of lab testing or the FDA's interest in regulating them. A regular reader of this blog has alerted me to the fact that Courtney C. Harper, Ph.D., from FDA’s Office of In Vitro Diagnostic Device Evaluation and Safety, delivered a lecture about IVDMIAs (see: Draft Guidance for Industry and FDA Staff: In Vitro Diagnostic Multivariate Indexed Assays (IVDMIAs) on March 15, 2007, as part of an AACC teleconference about this topic. Of interest to me were the following points by Dr. Harper that I have copied directly from her presentation:
- Potential examples of IVDMIAs include the following:
- A microarray that predicts colon cancer based on an RNA expression pattern
- An assay that integrates quantitative results from 7 immunoassays to obtain a qualitative "score" that predicts a person's risk of developing Alzheimer's disease
- A test that integrates a patient's age, gender, and genotype of 5 genes to diagnose cardiovascular disease
- Not all devices [i.e, tests] that use algorithms, software, or are multivariate are IVDMIAs; here are examples of tests that are NOT IVDMIAs
- Standard creatinine clearance determination
- A device that measures total cholesterol, HDL cholesterol, and triglycerides and determines LDL cholesterol concentration via a calculation
- An assay that measures the 25 ACOG/ACMG recommended mutations to report a patient's CFTR genotype
These points regarding IVDMIAs by an official representative of the FDA help to further clarify the issue. I have the following comments about them:
- It is now clear that the IVDMIA category, as defined by the FDA, includes both tissue microarrays, as in the case of MammaPrint and OncoType DX, and also panels of immunoassays of serum proteins. It's not clear to me why the example of "7 immunoassays" is suggested as compared to a "genotype of 5 genes."
- It is stated that MammaPrint can be used as a "predicate device" for similar IVDMIAs. This explains the following reference to MammaPrint in an Agendia press release.
- MammaPrint(R) represents a U.S. regulatory milestone as the first In Vitro Diagnostic Multivariate Index Assay (IVDMIA) to acquire market clearance from the FDA, and is the agency's first step toward standardizing these multi-gene expression tests.
- By providing market clearance to MammaPrint while the IVDMIA guidelines were still in draft form, the FDA is now able to provide a concrete example for the other tests in the same category that will undoubtedly follow. For its part, Agendia, the manufacturer of the test, obtains the advantage in the market of having the first test in this new category that has been cleared by the FDA.
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