September 2007 Clinical Laboratory News: News From the FDA

September 2007: Volume 33, Number 9

FDA Clarifies Definition of Multivariate Index Assays

FDA’s first draft guidance on in vitro multivariate index assays (IVDMIA), published in September 2006, surprised and worried many laboratorians who saw it as the beginning of increased regulatory oversight of laboratory-developed, or home-brew, assays. After extending the comment period and holding a public meeting about the controversial guidance in February, the FDA released a second draft guidance on July 26 titled “Draft Guidance for Industry, Clinical Laboratories, and FDA Staff: In Vitro Diagnostic Multivariate Index Assays,” in which the agency concentrates on the concerns voiced by stakeholders. The FDA said it received 60 comments that it used when writing the new guidance to bring greater clarity to trouble spots in the original.

The newly released guidance differs from the first in several key areas, especially in the retooled definition of IVDMIAs and added regulatory background to help manufacturers understand how the agency will view their products. The FDA now describes an IVDMIA as a device that “combines the values of multiple variables using an interpretation function to yield a single, patient-specific result” that clinicians couldn’t reach on their own. The guidance also aims to make it more clear what an IVDMIA is not, and provides detailed examples of non-IVDMIA devices, such as a clinical decision support tool that summarizes standard interpretation of patients’ information into a report that clinicians could do themselves, or common clinical calculations like creatinine clearance or estimated GFR. Other important differences include provisions for rare or orphan diagnostics, a grace period to allow time for compliance, and a commitment from the FDA to develop a guidance to help users bring CLIA programs into compliance with current regulations pertaining to use of analyte specific reagents, while avoiding conflicts between FDA and CLIA regulations, said Steve Gutman, MD, Director of the FDA’s Office of In Vitro Diagnostic Device Evaluation and Safety (OIVD). The comment period was scheduled to close on August 24. The OIVD announcement and link to the draft guidance is the FDA Web site.

Fully-Automated HCV Screening Test Cleared

Abbott (Abbott Park, Ill.) announced the FDA clearance of its Abbott PRISM HCV test. The test is approved to screen individual donations of blood and plasma for antibodies to HCV. The test is designed to run on the Abbott PRISM instrument, which also runs three types of HBV assays.

FDA Approves First Gene Test for Metastatic Breast Cancer

Veridex, LLC (Warren, N.J.) and the FDA announced the approval of the Gene-Search BLN assay, the first gene-based molecular diagnostic test to detect the spread of breast cancer into the lymph nodes with rapid results, which should help some women avoid repeat surgeries. The assay is approved for the rapid, intra-operative detection of metastases greater than 0.2 mm in sentinel lymph node tissue removed from breast cancer patients. Because it can be performed in 35 to 40 minutes, surgeons can evaluate the results and then take further action if necessary during the initial surgery. Sometimes women undergo a second surgery after an extensive, post-operative microscopic examination of the lymph node tissue finds more tumor cells. The FDA said that in clinical trials, the GeneSearch BLN assay gave fewer false-negative results, but slightly more false-positive results, when compared to immediate microscopic examination during surgery. 

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