FDA CLASSIFICATION RECLASSIFICATION OF IMMUNOHISTOCHEMISTRY REAGENTS - PRACTICAL CONSIDERATIONS/

The Food and Drug Administration (FDA) is responsible for regulating t he manufacture of in vitro diagnostic reagents. The level of regulatio n is linked to the level of risk posed by the product. Recently, the F DA published a proposed rule concerning the regulation of immunohistoc hemistry (IHC) reagents. The proposed rule states, in part, that the d egree of risk to the patient associated with the use of IHC products d epends on whether the product is used as an adjunct to conventional hi stopathology diagnostic techniques or provides information that is use d independent of the conventional diagnostic process. The ruling makes no distinction on the basis of demonstrated use in basic research or clinical laboratory medicine. Under the proposed rule, manufacturers o f IHC reagents would be required to submit a minimum of a premarket no tification for each reagent. The premarket notification, or 510(k), im poses a time consuming and expensive regulatory hurdle. For purposes o f comparison, biological stains represent a 510(k) exempt category of products. The present paper summarizes the FDA approval process as it relates to IHC products. Regulatory terms and conditions are defined. The implications of the proposed rule on the cost and availability of IHC reagents for clinical and research applications are discussed.