TABLE OF CONTENTS Diagnostics are mostly regulated as devices, but since the clinical usage aspects of diagnostics are more closely related to drug therapies, their development is discussed first in this section and device development (which covers several points relevant to diagnostic development) is discussed in Section 4.10.
Diagnostics are developed in two stages front-end investigative or exploratory research leads to the discovery of a potential marker or diagnostic protein, followed by extensive validation studies. The discovery is then validated in in vitro studies that include analysis of various stratification markers from tissue or serum samples to examine and optimize the accuracy, specificity, sensitivity, and reproducibility of the assay.
Assay development and optimization continues with a chosen clinical-testing technology platform. Before beginning clinical trials, a diagnostic kit that is user friendly, tested, and validated in a clinical environment is developed. The development of a commercial test method (with any needed change of technology platform) is completed before clinical trials are launched. A strong clinical correlation is validated using the configured clinical assay. The testing platform can be changed at this point, as long as the new technology platform can be shown to produce equivalent results. Larger companies now increasingly choose first to configure the assay on their already commercialized technological platform (e.g., immunodiagnostics), so that later optimization issues are reduced. This is akin to bringing final manufacturing considerations into the pre-clinical setting, as is increasingly being done in device and drug development.
The typical development stages and...
