Exploratory Biomarker Assays: Fit-for-purpose (FFP) Assay Parameters As Per Context-Of-Use (COU) 21 December, 2020   

Biomarker testing services are efficient enough to aid the industry and the researchers with their work in measuring different pathogenic, physiological, and therapy induced characteristics within the biological system. Thus, robust biomarker assays have become the necessity for transitioning the drug or the diagnostic device from its bench to its bedside.

These are considered as powerful approaches for eliciting the measurements of the indicators of the biological processes in both normal as well pathological conditions. Such biomarker services also contribute a lot to the response of pharmacological interventions. The analysis of these biomarkers in blood or other related body fluids either at the protein or DNA levels have been relied by medical practitioners for studying the progress of human diseases.

The biomarker services provided by several different biomarker assay testing labs for diagnosing and managing the clinical conditions in case of cancers, cardiovascular disorders, genetic disorders, immune responses, etc. Nevertheless, the biomarker assay development and validationapplication in research field has exploded out to burst crucial information pertaining to the biological reactions with its exposure to the novel therapeutic drug compounds.

The clinical biomarkers on the other hand, plays a key role in all the stages of the drug discovery and development. The biomarker assay services are widely employed for the early stages of the new chemical entity discovery for determining both the mechanistic as well as pharmacodynamic responses thereby guiding compound selection. Thus, such bioanalysis of the biomarkers helps in establishing the measurements of biological responses and deciding whether the potential therapeutic drug candidates can be further continued or stopped.

The basic focus of the biomarker assay development is constructing an assay that suffices the drug investigational goals. In short, the ‘fit-for-purpose’ is more widely applied. This is a level of validation in association with the medical product development tool. Methods for the biomarkers are labelled to be validated if and only if those set specific acceptance criteria for both accuracy as well as precision during the quality control testing over the wider range of the standard curve throughout the validation study. However, well in advance of validation, it becomes detrimental for the research to put many labs to work for performing a limited experiment sets without demonstrating the pre-set acceptance criteria. This assures that the established testing protocol is robust and will perform the same throughout the validation.

In case of early drug discovery and development, establishing compound selection or proof of concept, the sponsor preference determines the extent of the biomarker validation. Usually for US market, the FDA demands for full biomarker assay validation in those scenarios where the study highlights regulatory decision-making, or product labelling or ascertaining drug safety. In line with these biomarker assay validation guidance, evaluation of all relevant critical bioassay parameters should lie within the approved acceptance criteria for all determinants such as sensitivity, precision, accuracy, selectivity, dynamic range, etc. Furthermore, the biomarker validation shall also cover the parallelism, dilution effects, cover stability, prozone effect, etc.